Changed CSS color and set Tooltips and default value on dockWidget

71 files changed, 17626 insertions, 0 deletions

diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/__init__.py
new file mode 100644
index 0000000..276124d
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/__init__.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+from __future__ import absolute_import
+
+import locale
+import logging
+import os
+import warnings
+
+import sys
+
+# 2016-06-17 barry@debian.org: urllib3 1.14 added optional support for socks,
+# but if invoked (i.e. imported), it will issue a warning to stderr if socks
+# isn't available.  requests unconditionally imports urllib3's socks contrib
+# module, triggering this warning.  The warning breaks DEP-8 tests (because of
+# the stderr output) and is just plain annoying in normal usage.  I don't want
+# to add socks as yet another dependency for pip, nor do I want to allow-stder
+# in the DEP-8 tests, so just suppress the warning.  pdb tells me this has to
+# be done before the import of pip.vcs.
+from pip._vendor.urllib3.exceptions import DependencyWarning
+warnings.filterwarnings("ignore", category=DependencyWarning)  # noqa
+
+# We want to inject the use of SecureTransport as early as possible so that any
+# references or sessions or what have you are ensured to have it, however we
+# only want to do this in the case that we're running on macOS and the linked
+# OpenSSL is too old to handle TLSv1.2
+try:
+    import ssl
+except ImportError:
+    pass
+else:
+    # Checks for OpenSSL 1.0.1 on MacOS
+    if sys.platform == "darwin" and ssl.OPENSSL_VERSION_NUMBER < 0x1000100f:
+        try:
+            from pip._vendor.urllib3.contrib import securetransport
+        except (ImportError, OSError):
+            pass
+        else:
+            securetransport.inject_into_urllib3()
+
+from pip._internal.cli.autocompletion import autocomplete
+from pip._internal.cli.main_parser import parse_command
+from pip._internal.commands import commands_dict
+from pip._internal.exceptions import PipError
+from pip._internal.utils import deprecation
+from pip._internal.vcs import git, mercurial, subversion, bazaar  # noqa
+from pip._vendor.urllib3.exceptions import InsecureRequestWarning
+
+logger = logging.getLogger(__name__)
+
+# Hide the InsecureRequestWarning from urllib3
+warnings.filterwarnings("ignore", category=InsecureRequestWarning)
+
+
+def main(args=None):
+    if args is None:
+        args = sys.argv[1:]
+
+    # Configure our deprecation warnings to be sent through loggers
+    deprecation.install_warning_logger()
+
+    autocomplete()
+
+    try:
+        cmd_name, cmd_args = parse_command(args)
+    except PipError as exc:
+        sys.stderr.write("ERROR: %s" % exc)
+        sys.stderr.write(os.linesep)
+        sys.exit(1)
+
+    # Needed for locale.getpreferredencoding(False) to work
+    # in pip._internal.utils.encoding.auto_decode
+    try:
+        locale.setlocale(locale.LC_ALL, '')
+    except locale.Error as e:
+        # setlocale can apparently crash if locale are uninitialized
+        logger.debug("Ignoring error %s when setting locale", e)
+    command = commands_dict[cmd_name](isolated=("--isolated" in cmd_args))
+    return command.main(cmd_args)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/build_env.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/build_env.py
new file mode 100644
index 0000000..d744cc7
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/build_env.py
@@ -0,0 +1,215 @@
+"""Build Environment used for isolation during sdist building
+"""
+
+import logging
+import os
+import sys
+import textwrap
+from collections import OrderedDict
+from distutils.sysconfig import get_python_lib
+from sysconfig import get_paths
+
+from pip._vendor.pkg_resources import Requirement, VersionConflict, WorkingSet
+
+from pip import __file__ as pip_location
+from pip._internal.utils.misc import call_subprocess
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import open_spinner
+
+if MYPY_CHECK_RUNNING:
+    from typing import Tuple, Set, Iterable, Optional, List  # noqa: F401
+    from pip._internal.index import PackageFinder  # noqa: F401
+
+logger = logging.getLogger(__name__)
+
+
+class _Prefix:
+
+    def __init__(self, path):
+        # type: (str) -> None
+        self.path = path
+        self.setup = False
+        self.bin_dir = get_paths(
+            'nt' if os.name == 'nt' else 'posix_prefix',
+            vars={'base': path, 'platbase': path}
+        )['scripts']
+        # Note: prefer distutils' sysconfig to get the
+        # library paths so PyPy is correctly supported.
+        purelib = get_python_lib(plat_specific=False, prefix=path)
+        platlib = get_python_lib(plat_specific=True, prefix=path)
+        if purelib == platlib:
+            self.lib_dirs = [purelib]
+        else:
+            self.lib_dirs = [purelib, platlib]
+
+
+class BuildEnvironment(object):
+    """Creates and manages an isolated environment to install build deps
+    """
+
+    def __init__(self):
+        # type: () -> None
+        self._temp_dir = TempDirectory(kind="build-env")
+        self._temp_dir.create()
+
+        self._prefixes = OrderedDict((
+            (name, _Prefix(os.path.join(self._temp_dir.path, name)))
+            for name in ('normal', 'overlay')
+        ))
+
+        self._bin_dirs = []  # type: List[str]
+        self._lib_dirs = []  # type: List[str]
+        for prefix in reversed(list(self._prefixes.values())):
+            self._bin_dirs.append(prefix.bin_dir)
+            self._lib_dirs.extend(prefix.lib_dirs)
+
+        # Customize site to:
+        # - ensure .pth files are honored
+        # - prevent access to system site packages
+        system_sites = {
+            os.path.normcase(site) for site in (
+                get_python_lib(plat_specific=False),
+                get_python_lib(plat_specific=True),
+            )
+        }
+        self._site_dir = os.path.join(self._temp_dir.path, 'site')
+        if not os.path.exists(self._site_dir):
+            os.mkdir(self._site_dir)
+        with open(os.path.join(self._site_dir, 'sitecustomize.py'), 'w') as fp:
+            fp.write(textwrap.dedent(
+                '''
+                import os, site, sys
+
+                # First, drop system-sites related paths.
+                original_sys_path = sys.path[:]
+                known_paths = set()
+                for path in {system_sites!r}:
+                    site.addsitedir(path, known_paths=known_paths)
+                system_paths = set(
+                    os.path.normcase(path)
+                    for path in sys.path[len(original_sys_path):]
+                )
+                original_sys_path = [
+                    path for path in original_sys_path
+                    if os.path.normcase(path) not in system_paths
+                ]
+                sys.path = original_sys_path
+
+                # Second, add lib directories.
+                # ensuring .pth file are processed.
+                for path in {lib_dirs!r}:
+                    assert not path in sys.path
+                    site.addsitedir(path)
+                '''
+            ).format(system_sites=system_sites, lib_dirs=self._lib_dirs))
+
+    def __enter__(self):
+        self._save_env = {
+            name: os.environ.get(name, None)
+            for name in ('PATH', 'PYTHONNOUSERSITE', 'PYTHONPATH')
+        }
+
+        path = self._bin_dirs[:]
+        old_path = self._save_env['PATH']
+        if old_path:
+            path.extend(old_path.split(os.pathsep))
+
+        pythonpath = [self._site_dir]
+
+        os.environ.update({
+            'PATH': os.pathsep.join(path),
+            'PYTHONNOUSERSITE': '1',
+            'PYTHONPATH': os.pathsep.join(pythonpath),
+        })
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        for varname, old_value in self._save_env.items():
+            if old_value is None:
+                os.environ.pop(varname, None)
+            else:
+                os.environ[varname] = old_value
+
+    def cleanup(self):
+        # type: () -> None
+        self._temp_dir.cleanup()
+
+    def check_requirements(self, reqs):
+        # type: (Iterable[str]) -> Tuple[Set[Tuple[str, str]], Set[str]]
+        """Return 2 sets:
+            - conflicting requirements: set of (installed, wanted) reqs tuples
+            - missing requirements: set of reqs
+        """
+        missing = set()
+        conflicting = set()
+        if reqs:
+            ws = WorkingSet(self._lib_dirs)
+            for req in reqs:
+                try:
+                    if ws.find(Requirement.parse(req)) is None:
+                        missing.add(req)
+                except VersionConflict as e:
+                    conflicting.add((str(e.args[0].as_requirement()),
+                                     str(e.args[1])))
+        return conflicting, missing
+
+    def install_requirements(
+        self,
+        finder,  # type: PackageFinder
+        requirements,  # type: Iterable[str]
+        prefix_as_string,  # type: str
+        message  # type: Optional[str]
+    ):
+        # type: (...) -> None
+        prefix = self._prefixes[prefix_as_string]
+        assert not prefix.setup
+        prefix.setup = True
+        if not requirements:
+            return
+        args = [
+            sys.executable, os.path.dirname(pip_location), 'install',
+            '--ignore-installed', '--no-user', '--prefix', prefix.path,
+            '--no-warn-script-location',
+        ]  # type: List[str]
+        if logger.getEffectiveLevel() <= logging.DEBUG:
+            args.append('-v')
+        for format_control in ('no_binary', 'only_binary'):
+            formats = getattr(finder.format_control, format_control)
+            args.extend(('--' + format_control.replace('_', '-'),
+                         ','.join(sorted(formats or {':none:'}))))
+        if finder.index_urls:
+            args.extend(['-i', finder.index_urls[0]])
+            for extra_index in finder.index_urls[1:]:
+                args.extend(['--extra-index-url', extra_index])
+        else:
+            args.append('--no-index')
+        for link in finder.find_links:
+            args.extend(['--find-links', link])
+        for _, host, _ in finder.secure_origins:
+            args.extend(['--trusted-host', host])
+        if finder.allow_all_prereleases:
+            args.append('--pre')
+        args.append('--')
+        args.extend(requirements)
+        with open_spinner(message) as spinner:
+            call_subprocess(args, show_stdout=False, spinner=spinner)
+
+
+class NoOpBuildEnvironment(BuildEnvironment):
+    """A no-op drop-in replacement for BuildEnvironment
+    """
+
+    def __init__(self):
+        pass
+
+    def __enter__(self):
+        pass
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        pass
+
+    def cleanup(self):
+        pass
+
+    def install_requirements(self, finder, requirements, prefix, message):
+        raise NotImplementedError()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cache.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cache.py
new file mode 100644
index 0000000..eb295c4
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cache.py
@@ -0,0 +1,224 @@
+"""Cache Management
+"""
+
+import errno
+import hashlib
+import logging
+import os
+
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.download import path_to_url
+from pip._internal.models.link import Link
+from pip._internal.utils.compat import expanduser
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.wheel import InvalidWheelFilename, Wheel
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Set, List, Any  # noqa: F401
+    from pip._internal.index import FormatControl  # noqa: F401
+
+logger = logging.getLogger(__name__)
+
+
+class Cache(object):
+    """An abstract class - provides cache directories for data from links
+
+
+        :param cache_dir: The root of the cache.
+        :param format_control: An object of FormatControl class to limit
+            binaries being read from the cache.
+        :param allowed_formats: which formats of files the cache should store.
+            ('binary' and 'source' are the only allowed values)
+    """
+
+    def __init__(self, cache_dir, format_control, allowed_formats):
+        # type: (str, FormatControl, Set[str]) -> None
+        super(Cache, self).__init__()
+        self.cache_dir = expanduser(cache_dir) if cache_dir else None
+        self.format_control = format_control
+        self.allowed_formats = allowed_formats
+
+        _valid_formats = {"source", "binary"}
+        assert self.allowed_formats.union(_valid_formats) == _valid_formats
+
+    def _get_cache_path_parts(self, link):
+        # type: (Link) -> List[str]
+        """Get parts of part that must be os.path.joined with cache_dir
+        """
+
+        # We want to generate an url to use as our cache key, we don't want to
+        # just re-use the URL because it might have other items in the fragment
+        # and we don't care about those.
+        key_parts = [link.url_without_fragment]
+        if link.hash_name is not None and link.hash is not None:
+            key_parts.append("=".join([link.hash_name, link.hash]))
+        key_url = "#".join(key_parts)
+
+        # Encode our key url with sha224, we'll use this because it has similar
+        # security properties to sha256, but with a shorter total output (and
+        # thus less secure). However the differences don't make a lot of
+        # difference for our use case here.
+        hashed = hashlib.sha224(key_url.encode()).hexdigest()
+
+        # We want to nest the directories some to prevent having a ton of top
+        # level directories where we might run out of sub directories on some
+        # FS.
+        parts = [hashed[:2], hashed[2:4], hashed[4:6], hashed[6:]]
+
+        return parts
+
+    def _get_candidates(self, link, package_name):
+        # type: (Link, Optional[str]) -> List[Any]
+        can_not_cache = (
+            not self.cache_dir or
+            not package_name or
+            not link
+        )
+        if can_not_cache:
+            return []
+
+        canonical_name = canonicalize_name(package_name)
+        formats = self.format_control.get_allowed_formats(
+            canonical_name
+        )
+        if not self.allowed_formats.intersection(formats):
+            return []
+
+        root = self.get_path_for_link(link)
+        try:
+            return os.listdir(root)
+        except OSError as err:
+            if err.errno in {errno.ENOENT, errno.ENOTDIR}:
+                return []
+            raise
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        """Return a directory to store cached items in for link.
+        """
+        raise NotImplementedError()
+
+    def get(self, link, package_name):
+        # type: (Link, Optional[str]) -> Link
+        """Returns a link to a cached item if it exists, otherwise returns the
+        passed link.
+        """
+        raise NotImplementedError()
+
+    def _link_for_candidate(self, link, candidate):
+        # type: (Link, str) -> Link
+        root = self.get_path_for_link(link)
+        path = os.path.join(root, candidate)
+
+        return Link(path_to_url(path))
+
+    def cleanup(self):
+        # type: () -> None
+        pass
+
+
+class SimpleWheelCache(Cache):
+    """A cache of wheels for future installs.
+    """
+
+    def __init__(self, cache_dir, format_control):
+        # type: (str, FormatControl) -> None
+        super(SimpleWheelCache, self).__init__(
+            cache_dir, format_control, {"binary"}
+        )
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        """Return a directory to store cached wheels for link
+
+        Because there are M wheels for any one sdist, we provide a directory
+        to cache them in, and then consult that directory when looking up
+        cache hits.
+
+        We only insert things into the cache if they have plausible version
+        numbers, so that we don't contaminate the cache with things that were
+        not unique. E.g. ./package might have dozens of installs done for it
+        and build a version of 0.0...and if we built and cached a wheel, we'd
+        end up using the same wheel even if the source has been edited.
+
+        :param link: The link of the sdist for which this will cache wheels.
+        """
+        parts = self._get_cache_path_parts(link)
+
+        # Store wheels within the root cache_dir
+        return os.path.join(self.cache_dir, "wheels", *parts)
+
+    def get(self, link, package_name):
+        # type: (Link, Optional[str]) -> Link
+        candidates = []
+
+        for wheel_name in self._get_candidates(link, package_name):
+            try:
+                wheel = Wheel(wheel_name)
+            except InvalidWheelFilename:
+                continue
+            if not wheel.supported():
+                # Built for a different python/arch/etc
+                continue
+            candidates.append((wheel.support_index_min(), wheel_name))
+
+        if not candidates:
+            return link
+
+        return self._link_for_candidate(link, min(candidates)[1])
+
+
+class EphemWheelCache(SimpleWheelCache):
+    """A SimpleWheelCache that creates it's own temporary cache directory
+    """
+
+    def __init__(self, format_control):
+        # type: (FormatControl) -> None
+        self._temp_dir = TempDirectory(kind="ephem-wheel-cache")
+        self._temp_dir.create()
+
+        super(EphemWheelCache, self).__init__(
+            self._temp_dir.path, format_control
+        )
+
+    def cleanup(self):
+        # type: () -> None
+        self._temp_dir.cleanup()
+
+
+class WheelCache(Cache):
+    """Wraps EphemWheelCache and SimpleWheelCache into a single Cache
+
+    This Cache allows for gracefully degradation, using the ephem wheel cache
+    when a certain link is not found in the simple wheel cache first.
+    """
+
+    def __init__(self, cache_dir, format_control):
+        # type: (str, FormatControl) -> None
+        super(WheelCache, self).__init__(
+            cache_dir, format_control, {'binary'}
+        )
+        self._wheel_cache = SimpleWheelCache(cache_dir, format_control)
+        self._ephem_cache = EphemWheelCache(format_control)
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        return self._wheel_cache.get_path_for_link(link)
+
+    def get_ephem_path_for_link(self, link):
+        # type: (Link) -> str
+        return self._ephem_cache.get_path_for_link(link)
+
+    def get(self, link, package_name):
+        # type: (Link, Optional[str]) -> Link
+        retval = self._wheel_cache.get(link, package_name)
+        if retval is link:
+            retval = self._ephem_cache.get(link, package_name)
+        return retval
+
+    def cleanup(self):
+        # type: () -> None
+        self._wheel_cache.cleanup()
+        self._ephem_cache.cleanup()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/__init__.py
new file mode 100644
index 0000000..e589bb9
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/__init__.py
@@ -0,0 +1,4 @@
+"""Subpackage containing all of pip's command line interface related code
+"""
+
+# This file intentionally does not import submodules
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/autocompletion.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/autocompletion.py
new file mode 100644
index 0000000..0a04199
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/autocompletion.py
@@ -0,0 +1,152 @@
+"""Logic that powers autocompletion installed by ``pip completion``.
+"""
+
+import optparse
+import os
+import sys
+
+from pip._internal.cli.main_parser import create_main_parser
+from pip._internal.commands import commands_dict, get_summaries
+from pip._internal.utils.misc import get_installed_distributions
+
+
+def autocomplete():
+    """Entry Point for completion of main and subcommand options.
+    """
+    # Don't complete if user hasn't sourced bash_completion file.
+    if 'PIP_AUTO_COMPLETE' not in os.environ:
+        return
+    cwords = os.environ['COMP_WORDS'].split()[1:]
+    cword = int(os.environ['COMP_CWORD'])
+    try:
+        current = cwords[cword - 1]
+    except IndexError:
+        current = ''
+
+    subcommands = [cmd for cmd, summary in get_summaries()]
+    options = []
+    # subcommand
+    try:
+        subcommand_name = [w for w in cwords if w in subcommands][0]
+    except IndexError:
+        subcommand_name = None
+
+    parser = create_main_parser()
+    # subcommand options
+    if subcommand_name:
+        # special case: 'help' subcommand has no options
+        if subcommand_name == 'help':
+            sys.exit(1)
+        # special case: list locally installed dists for show and uninstall
+        should_list_installed = (
+            subcommand_name in ['show', 'uninstall'] and
+            not current.startswith('-')
+        )
+        if should_list_installed:
+            installed = []
+            lc = current.lower()
+            for dist in get_installed_distributions(local_only=True):
+                if dist.key.startswith(lc) and dist.key not in cwords[1:]:
+                    installed.append(dist.key)
+            # if there are no dists installed, fall back to option completion
+            if installed:
+                for dist in installed:
+                    print(dist)
+                sys.exit(1)
+
+        subcommand = commands_dict[subcommand_name]()
+
+        for opt in subcommand.parser.option_list_all:
+            if opt.help != optparse.SUPPRESS_HELP:
+                for opt_str in opt._long_opts + opt._short_opts:
+                    options.append((opt_str, opt.nargs))
+
+        # filter out previously specified options from available options
+        prev_opts = [x.split('=')[0] for x in cwords[1:cword - 1]]
+        options = [(x, v) for (x, v) in options if x not in prev_opts]
+        # filter options by current input
+        options = [(k, v) for k, v in options if k.startswith(current)]
+        # get completion type given cwords and available subcommand options
+        completion_type = get_path_completion_type(
+            cwords, cword, subcommand.parser.option_list_all,
+        )
+        # get completion files and directories if ``completion_type`` is
+        # ``<file>``, ``<dir>`` or ``<path>``
+        if completion_type:
+            options = auto_complete_paths(current, completion_type)
+            options = ((opt, 0) for opt in options)
+        for option in options:
+            opt_label = option[0]
+            # append '=' to options which require args
+            if option[1] and option[0][:2] == "--":
+                opt_label += '='
+            print(opt_label)
+    else:
+        # show main parser options only when necessary
+
+        opts = [i.option_list for i in parser.option_groups]
+        opts.append(parser.option_list)
+        opts = (o for it in opts for o in it)
+        if current.startswith('-'):
+            for opt in opts:
+                if opt.help != optparse.SUPPRESS_HELP:
+                    subcommands += opt._long_opts + opt._short_opts
+        else:
+            # get completion type given cwords and all available options
+            completion_type = get_path_completion_type(cwords, cword, opts)
+            if completion_type:
+                subcommands = auto_complete_paths(current, completion_type)
+
+        print(' '.join([x for x in subcommands if x.startswith(current)]))
+    sys.exit(1)
+
+
+def get_path_completion_type(cwords, cword, opts):
+    """Get the type of path completion (``file``, ``dir``, ``path`` or None)
+
+    :param cwords: same as the environmental variable ``COMP_WORDS``
+    :param cword: same as the environmental variable ``COMP_CWORD``
+    :param opts: The available options to check
+    :return: path completion type (``file``, ``dir``, ``path`` or None)
+    """
+    if cword < 2 or not cwords[cword - 2].startswith('-'):
+        return
+    for opt in opts:
+        if opt.help == optparse.SUPPRESS_HELP:
+            continue
+        for o in str(opt).split('/'):
+            if cwords[cword - 2].split('=')[0] == o:
+                if not opt.metavar or any(
+                        x in ('path', 'file', 'dir')
+                        for x in opt.metavar.split('/')):
+                    return opt.metavar
+
+
+def auto_complete_paths(current, completion_type):
+    """If ``completion_type`` is ``file`` or ``path``, list all regular files
+    and directories starting with ``current``; otherwise only list directories
+    starting with ``current``.
+
+    :param current: The word to be completed
+    :param completion_type: path completion type(`file`, `path` or `dir`)i
+    :return: A generator of regular files and/or directories
+    """
+    directory, filename = os.path.split(current)
+    current_path = os.path.abspath(directory)
+    # Don't complete paths if they can't be accessed
+    if not os.access(current_path, os.R_OK):
+        return
+    filename = os.path.normcase(filename)
+    # list all files that start with ``filename``
+    file_list = (x for x in os.listdir(current_path)
+                 if os.path.normcase(x).startswith(filename))
+    for f in file_list:
+        opt = os.path.join(current_path, f)
+        comp_file = os.path.normcase(os.path.join(directory, f))
+        # complete regular files when there is not ``<dir>`` after option
+        # complete directories when there is ``<file>``, ``<path>`` or
+        # ``<dir>``after option
+        if completion_type != 'dir' and os.path.isfile(opt):
+            yield comp_file
+        elif os.path.isdir(opt):
+            yield os.path.join(comp_file, '')
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/base_command.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/base_command.py
new file mode 100644
index 0000000..3ceea49
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/base_command.py
@@ -0,0 +1,341 @@
+"""Base Command class, and related routines"""
+from __future__ import absolute_import, print_function
+
+import logging
+import logging.config
+import optparse
+import os
+import platform
+import sys
+import traceback
+
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.parser import (
+    ConfigOptionParser, UpdatingDefaultsHelpFormatter,
+)
+from pip._internal.cli.status_codes import (
+    ERROR, PREVIOUS_BUILD_DIR_ERROR, SUCCESS, UNKNOWN_ERROR,
+    VIRTUALENV_NOT_FOUND,
+)
+from pip._internal.download import PipSession
+from pip._internal.exceptions import (
+    BadCommand, CommandError, InstallationError, PreviousBuildDirError,
+    UninstallationError,
+)
+from pip._internal.index import PackageFinder
+from pip._internal.locations import running_under_virtualenv
+from pip._internal.req.constructors import (
+    install_req_from_editable, install_req_from_line,
+)
+from pip._internal.req.req_file import parse_requirements
+from pip._internal.utils.deprecation import deprecated
+from pip._internal.utils.logging import BrokenStdoutLoggingError, setup_logging
+from pip._internal.utils.misc import (
+    get_prog, normalize_path, redact_password_from_url,
+)
+from pip._internal.utils.outdated import pip_version_check
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, List, Tuple, Any  # noqa: F401
+    from optparse import Values  # noqa: F401
+    from pip._internal.cache import WheelCache  # noqa: F401
+    from pip._internal.req.req_set import RequirementSet  # noqa: F401
+
+__all__ = ['Command']
+
+logger = logging.getLogger(__name__)
+
+
+class Command(object):
+    name = None  # type: Optional[str]
+    usage = None  # type: Optional[str]
+    hidden = False  # type: bool
+    ignore_require_venv = False  # type: bool
+
+    def __init__(self, isolated=False):
+        # type: (bool) -> None
+        parser_kw = {
+            'usage': self.usage,
+            'prog': '%s %s' % (get_prog(), self.name),
+            'formatter': UpdatingDefaultsHelpFormatter(),
+            'add_help_option': False,
+            'name': self.name,
+            'description': self.__doc__,
+            'isolated': isolated,
+        }
+
+        self.parser = ConfigOptionParser(**parser_kw)
+
+        # Commands should add options to this option group
+        optgroup_name = '%s Options' % self.name.capitalize()
+        self.cmd_opts = optparse.OptionGroup(self.parser, optgroup_name)
+
+        # Add the general options
+        gen_opts = cmdoptions.make_option_group(
+            cmdoptions.general_group,
+            self.parser,
+        )
+        self.parser.add_option_group(gen_opts)
+
+    def run(self, options, args):
+        # type: (Values, List[Any]) -> Any
+        raise NotImplementedError
+
+    def _build_session(self, options, retries=None, timeout=None):
+        # type: (Values, Optional[int], Optional[int]) -> PipSession
+        session = PipSession(
+            cache=(
+                normalize_path(os.path.join(options.cache_dir, "http"))
+                if options.cache_dir else None
+            ),
+            retries=retries if retries is not None else options.retries,
+            insecure_hosts=options.trusted_hosts,
+        )
+
+        # Handle custom ca-bundles from the user
+        if options.cert:
+            session.verify = options.cert
+
+        # Handle SSL client certificate
+        if options.client_cert:
+            session.cert = options.client_cert
+
+        # Handle timeouts
+        if options.timeout or timeout:
+            session.timeout = (
+                timeout if timeout is not None else options.timeout
+            )
+
+        # Handle configured proxies
+        if options.proxy:
+            session.proxies = {
+                "http": options.proxy,
+                "https": options.proxy,
+            }
+
+        # Determine if we can prompt the user for authentication or not
+        session.auth.prompting = not options.no_input
+
+        return session
+
+    def parse_args(self, args):
+        # type: (List[str]) -> Tuple
+        # factored out for testability
+        return self.parser.parse_args(args)
+
+    def main(self, args):
+        # type: (List[str]) -> int
+        options, args = self.parse_args(args)
+
+        # Set verbosity so that it can be used elsewhere.
+        self.verbosity = options.verbose - options.quiet
+
+        level_number = setup_logging(
+            verbosity=self.verbosity,
+            no_color=options.no_color,
+            user_log_file=options.log,
+        )
+
+        if sys.version_info[:2] == (3, 4):
+            deprecated(
+                "Python 3.4 support has been deprecated. pip 19.1 will be the "
+                "last one supporting it. Please upgrade your Python as Python "
+                "3.4 won't be maintained after March 2019 (cf PEP 429).",
+                replacement=None,
+                gone_in='19.2',
+            )
+        elif sys.version_info[:2] == (2, 7):
+            message = (
+                "A future version of pip will drop support for Python 2.7."
+            )
+            if platform.python_implementation() == "CPython":
+                message = (
+                    "Python 2.7 will reach the end of its life on January "
+                    "1st, 2020. Please upgrade your Python as Python 2.7 "
+                    "won't be maintained after that date. "
+                ) + message
+            deprecated(message, replacement=None, gone_in=None)
+
+        # TODO: Try to get these passing down from the command?
+        #       without resorting to os.environ to hold these.
+        #       This also affects isolated builds and it should.
+
+        if options.no_input:
+            os.environ['PIP_NO_INPUT'] = '1'
+
+        if options.exists_action:
+            os.environ['PIP_EXISTS_ACTION'] = ' '.join(options.exists_action)
+
+        if options.require_venv and not self.ignore_require_venv:
+            # If a venv is required check if it can really be found
+            if not running_under_virtualenv():
+                logger.critical(
+                    'Could not find an activated virtualenv (required).'
+                )
+                sys.exit(VIRTUALENV_NOT_FOUND)
+
+        try:
+            status = self.run(options, args)
+            # FIXME: all commands should return an exit status
+            # and when it is done, isinstance is not needed anymore
+            if isinstance(status, int):
+                return status
+        except PreviousBuildDirError as exc:
+            logger.critical(str(exc))
+            logger.debug('Exception information:', exc_info=True)
+
+            return PREVIOUS_BUILD_DIR_ERROR
+        except (InstallationError, UninstallationError, BadCommand) as exc:
+            logger.critical(str(exc))
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except CommandError as exc:
+            logger.critical('ERROR: %s', exc)
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except BrokenStdoutLoggingError:
+            # Bypass our logger and write any remaining messages to stderr
+            # because stdout no longer works.
+            print('ERROR: Pipe to stdout was broken', file=sys.stderr)
+            if level_number <= logging.DEBUG:
+                traceback.print_exc(file=sys.stderr)
+
+            return ERROR
+        except KeyboardInterrupt:
+            logger.critical('Operation cancelled by user')
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except BaseException:
+            logger.critical('Exception:', exc_info=True)
+
+            return UNKNOWN_ERROR
+        finally:
+            allow_version_check = (
+                # Does this command have the index_group options?
+                hasattr(options, "no_index") and
+                # Is this command allowed to perform this check?
+                not (options.disable_pip_version_check or options.no_index)
+            )
+            # Check if we're using the latest version of pip available
+            if allow_version_check:
+                session = self._build_session(
+                    options,
+                    retries=0,
+                    timeout=min(5, options.timeout)
+                )
+                with session:
+                    pip_version_check(session, options)
+
+            # Shutdown the logging module
+            logging.shutdown()
+
+        return SUCCESS
+
+
+class RequirementCommand(Command):
+
+    @staticmethod
+    def populate_requirement_set(requirement_set,  # type: RequirementSet
+                                 args,             # type: List[str]
+                                 options,          # type: Values
+                                 finder,           # type: PackageFinder
+                                 session,          # type: PipSession
+                                 name,             # type: str
+                                 wheel_cache       # type: Optional[WheelCache]
+                                 ):
+        # type: (...) -> None
+        """
+        Marshal cmd line args into a requirement set.
+        """
+        # NOTE: As a side-effect, options.require_hashes and
+        #       requirement_set.require_hashes may be updated
+
+        for filename in options.constraints:
+            for req_to_add in parse_requirements(
+                    filename,
+                    constraint=True, finder=finder, options=options,
+                    session=session, wheel_cache=wheel_cache):
+                req_to_add.is_direct = True
+                requirement_set.add_requirement(req_to_add)
+
+        for req in args:
+            req_to_add = install_req_from_line(
+                req, None, isolated=options.isolated_mode,
+                use_pep517=options.use_pep517,
+                wheel_cache=wheel_cache
+            )
+            req_to_add.is_direct = True
+            requirement_set.add_requirement(req_to_add)
+
+        for req in options.editables:
+            req_to_add = install_req_from_editable(
+                req,
+                isolated=options.isolated_mode,
+                use_pep517=options.use_pep517,
+                wheel_cache=wheel_cache
+            )
+            req_to_add.is_direct = True
+            requirement_set.add_requirement(req_to_add)
+
+        for filename in options.requirements:
+            for req_to_add in parse_requirements(
+                    filename,
+                    finder=finder, options=options, session=session,
+                    wheel_cache=wheel_cache,
+                    use_pep517=options.use_pep517):
+                req_to_add.is_direct = True
+                requirement_set.add_requirement(req_to_add)
+        # If --require-hashes was a line in a requirements file, tell
+        # RequirementSet about it:
+        requirement_set.require_hashes = options.require_hashes
+
+        if not (args or options.editables or options.requirements):
+            opts = {'name': name}
+            if options.find_links:
+                raise CommandError(
+                    'You must give at least one requirement to %(name)s '
+                    '(maybe you meant "pip %(name)s %(links)s"?)' %
+                    dict(opts, links=' '.join(options.find_links)))
+            else:
+                raise CommandError(
+                    'You must give at least one requirement to %(name)s '
+                    '(see "pip help %(name)s")' % opts)
+
+    def _build_package_finder(
+        self,
+        options,               # type: Values
+        session,               # type: PipSession
+        platform=None,         # type: Optional[str]
+        python_versions=None,  # type: Optional[List[str]]
+        abi=None,              # type: Optional[str]
+        implementation=None    # type: Optional[str]
+    ):
+        # type: (...) -> PackageFinder
+        """
+        Create a package finder appropriate to this requirement command.
+        """
+        index_urls = [options.index_url] + options.extra_index_urls
+        if options.no_index:
+            logger.debug(
+                'Ignoring indexes: %s',
+                ','.join(redact_password_from_url(url) for url in index_urls),
+            )
+            index_urls = []
+
+        return PackageFinder(
+            find_links=options.find_links,
+            format_control=options.format_control,
+            index_urls=index_urls,
+            trusted_hosts=options.trusted_hosts,
+            allow_all_prereleases=options.pre,
+            session=session,
+            platform=platform,
+            versions=python_versions,
+            abi=abi,
+            implementation=implementation,
+            prefer_binary=options.prefer_binary,
+        )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/cmdoptions.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/cmdoptions.py
new file mode 100644
index 0000000..5cf5ee9
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/cmdoptions.py
@@ -0,0 +1,809 @@
+"""
+shared options and groups
+
+The principle here is to define options once, but *not* instantiate them
+globally. One reason being that options with action='append' can carry state
+between parses. pip parses general options twice internally, and shouldn't
+pass on state. To be consistent, all options will follow this design.
+
+"""
+from __future__ import absolute_import
+
+import textwrap
+import warnings
+from distutils.util import strtobool
+from functools import partial
+from optparse import SUPPRESS_HELP, Option, OptionGroup
+
+from pip._internal.exceptions import CommandError
+from pip._internal.locations import USER_CACHE_DIR, src_prefix
+from pip._internal.models.format_control import FormatControl
+from pip._internal.models.index import PyPI
+from pip._internal.utils.hashes import STRONG_HASHES
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import BAR_TYPES
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Callable, Dict, List, Optional, Union  # noqa: F401
+    from optparse import OptionParser, Values  # noqa: F401
+    from pip._internal.cli.parser import ConfigOptionParser  # noqa: F401
+
+
+def raise_option_error(parser, option, msg):
+    """
+    Raise an option parsing error using parser.error().
+
+    Args:
+      parser: an OptionParser instance.
+      option: an Option instance.
+      msg: the error text.
+    """
+    msg = '{} error: {}'.format(option, msg)
+    msg = textwrap.fill(' '.join(msg.split()))
+    parser.error(msg)
+
+
+def make_option_group(group, parser):
+    # type: (Dict[str, Any], ConfigOptionParser) -> OptionGroup
+    """
+    Return an OptionGroup object
+    group  -- assumed to be dict with 'name' and 'options' keys
+    parser -- an optparse Parser
+    """
+    option_group = OptionGroup(parser, group['name'])
+    for option in group['options']:
+        option_group.add_option(option())
+    return option_group
+
+
+def check_install_build_global(options, check_options=None):
+    # type: (Values, Optional[Values]) -> None
+    """Disable wheels if per-setup.py call options are set.
+
+    :param options: The OptionParser options to update.
+    :param check_options: The options to check, if not supplied defaults to
+        options.
+    """
+    if check_options is None:
+        check_options = options
+
+    def getname(n):
+        return getattr(check_options, n, None)
+    names = ["build_options", "global_options", "install_options"]
+    if any(map(getname, names)):
+        control = options.format_control
+        control.disallow_binaries()
+        warnings.warn(
+            'Disabling all use of wheels due to the use of --build-options '
+            '/ --global-options / --install-options.', stacklevel=2,
+        )
+
+
+def check_dist_restriction(options, check_target=False):
+    # type: (Values, bool) -> None
+    """Function for determining if custom platform options are allowed.
+
+    :param options: The OptionParser options.
+    :param check_target: Whether or not to check if --target is being used.
+    """
+    dist_restriction_set = any([
+        options.python_version,
+        options.platform,
+        options.abi,
+        options.implementation,
+    ])
+
+    binary_only = FormatControl(set(), {':all:'})
+    sdist_dependencies_allowed = (
+        options.format_control != binary_only and
+        not options.ignore_dependencies
+    )
+
+    # Installations or downloads using dist restrictions must not combine
+    # source distributions and dist-specific wheels, as they are not
+    # gauranteed to be locally compatible.
+    if dist_restriction_set and sdist_dependencies_allowed:
+        raise CommandError(
+            "When restricting platform and interpreter constraints using "
+            "--python-version, --platform, --abi, or --implementation, "
+            "either --no-deps must be set, or --only-binary=:all: must be "
+            "set and --no-binary must not be set (or must be set to "
+            ":none:)."
+        )
+
+    if check_target:
+        if dist_restriction_set and not options.target_dir:
+            raise CommandError(
+                "Can not use any platform or abi specific options unless "
+                "installing via '--target'"
+            )
+
+
+###########
+# options #
+###########
+
+help_ = partial(
+    Option,
+    '-h', '--help',
+    dest='help',
+    action='help',
+    help='Show help.',
+)  # type: Callable[..., Option]
+
+isolated_mode = partial(
+    Option,
+    "--isolated",
+    dest="isolated_mode",
+    action="store_true",
+    default=False,
+    help=(
+        "Run pip in an isolated mode, ignoring environment variables and user "
+        "configuration."
+    ),
+)  # type: Callable[..., Option]
+
+require_virtualenv = partial(
+    Option,
+    # Run only if inside a virtualenv, bail if not.
+    '--require-virtualenv', '--require-venv',
+    dest='require_venv',
+    action='store_true',
+    default=False,
+    help=SUPPRESS_HELP
+)  # type: Callable[..., Option]
+
+verbose = partial(
+    Option,
+    '-v', '--verbose',
+    dest='verbose',
+    action='count',
+    default=0,
+    help='Give more output. Option is additive, and can be used up to 3 times.'
+)  # type: Callable[..., Option]
+
+no_color = partial(
+    Option,
+    '--no-color',
+    dest='no_color',
+    action='store_true',
+    default=False,
+    help="Suppress colored output",
+)  # type: Callable[..., Option]
+
+version = partial(
+    Option,
+    '-V', '--version',
+    dest='version',
+    action='store_true',
+    help='Show version and exit.',
+)  # type: Callable[..., Option]
+
+quiet = partial(
+    Option,
+    '-q', '--quiet',
+    dest='quiet',
+    action='count',
+    default=0,
+    help=(
+        'Give less output. Option is additive, and can be used up to 3'
+        ' times (corresponding to WARNING, ERROR, and CRITICAL logging'
+        ' levels).'
+    ),
+)  # type: Callable[..., Option]
+
+progress_bar = partial(
+    Option,
+    '--progress-bar',
+    dest='progress_bar',
+    type='choice',
+    choices=list(BAR_TYPES.keys()),
+    default='on',
+    help=(
+        'Specify type of progress to be displayed [' +
+        '|'.join(BAR_TYPES.keys()) + '] (default: %default)'
+    ),
+)  # type: Callable[..., Option]
+
+log = partial(
+    Option,
+    "--log", "--log-file", "--local-log",
+    dest="log",
+    metavar="path",
+    help="Path to a verbose appending log."
+)  # type: Callable[..., Option]
+
+no_input = partial(
+    Option,
+    # Don't ask for input
+    '--no-input',
+    dest='no_input',
+    action='store_true',
+    default=False,
+    help=SUPPRESS_HELP
+)  # type: Callable[..., Option]
+
+proxy = partial(
+    Option,
+    '--proxy',
+    dest='proxy',
+    type='str',
+    default='',
+    help="Specify a proxy in the form [user:passwd@]proxy.server:port."
+)  # type: Callable[..., Option]
+
+retries = partial(
+    Option,
+    '--retries',
+    dest='retries',
+    type='int',
+    default=5,
+    help="Maximum number of retries each connection should attempt "
+         "(default %default times).",
+)  # type: Callable[..., Option]
+
+timeout = partial(
+    Option,
+    '--timeout', '--default-timeout',
+    metavar='sec',
+    dest='timeout',
+    type='float',
+    default=15,
+    help='Set the socket timeout (default %default seconds).',
+)  # type: Callable[..., Option]
+
+skip_requirements_regex = partial(
+    Option,
+    # A regex to be used to skip requirements
+    '--skip-requirements-regex',
+    dest='skip_requirements_regex',
+    type='str',
+    default='',
+    help=SUPPRESS_HELP,
+)  # type: Callable[..., Option]
+
+
+def exists_action():
+    # type: () -> Option
+    return Option(
+        # Option when path already exist
+        '--exists-action',
+        dest='exists_action',
+        type='choice',
+        choices=['s', 'i', 'w', 'b', 'a'],
+        default=[],
+        action='append',
+        metavar='action',
+        help="Default action when a path already exists: "
+             "(s)witch, (i)gnore, (w)ipe, (b)ackup, (a)bort).",
+    )
+
+
+cert = partial(
+    Option,
+    '--cert',
+    dest='cert',
+    type='str',
+    metavar='path',
+    help="Path to alternate CA bundle.",
+)  # type: Callable[..., Option]
+
+client_cert = partial(
+    Option,
+    '--client-cert',
+    dest='client_cert',
+    type='str',
+    default=None,
+    metavar='path',
+    help="Path to SSL client certificate, a single file containing the "
+         "private key and the certificate in PEM format.",
+)  # type: Callable[..., Option]
+
+index_url = partial(
+    Option,
+    '-i', '--index-url', '--pypi-url',
+    dest='index_url',
+    metavar='URL',
+    default=PyPI.simple_url,
+    help="Base URL of Python Package Index (default %default). "
+         "This should point to a repository compliant with PEP 503 "
+         "(the simple repository API) or a local directory laid out "
+         "in the same format.",
+)  # type: Callable[..., Option]
+
+
+def extra_index_url():
+    return Option(
+        '--extra-index-url',
+        dest='extra_index_urls',
+        metavar='URL',
+        action='append',
+        default=[],
+        help="Extra URLs of package indexes to use in addition to "
+             "--index-url. Should follow the same rules as "
+             "--index-url.",
+    )
+
+
+no_index = partial(
+    Option,
+    '--no-index',
+    dest='no_index',
+    action='store_true',
+    default=False,
+    help='Ignore package index (only looking at --find-links URLs instead).',
+)  # type: Callable[..., Option]
+
+
+def find_links():
+    # type: () -> Option
+    return Option(
+        '-f', '--find-links',
+        dest='find_links',
+        action='append',
+        default=[],
+        metavar='url',
+        help="If a url or path to an html file, then parse for links to "
+             "archives. If a local path or file:// url that's a directory, "
+             "then look for archives in the directory listing.",
+    )
+
+
+def trusted_host():
+    # type: () -> Option
+    return Option(
+        "--trusted-host",
+        dest="trusted_hosts",
+        action="append",
+        metavar="HOSTNAME",
+        default=[],
+        help="Mark this host as trusted, even though it does not have valid "
+             "or any HTTPS.",
+    )
+
+
+def constraints():
+    # type: () -> Option
+    return Option(
+        '-c', '--constraint',
+        dest='constraints',
+        action='append',
+        default=[],
+        metavar='file',
+        help='Constrain versions using the given constraints file. '
+        'This option can be used multiple times.'
+    )
+
+
+def requirements():
+    # type: () -> Option
+    return Option(
+        '-r', '--requirement',
+        dest='requirements',
+        action='append',
+        default=[],
+        metavar='file',
+        help='Install from the given requirements file. '
+        'This option can be used multiple times.'
+    )
+
+
+def editable():
+    # type: () -> Option
+    return Option(
+        '-e', '--editable',
+        dest='editables',
+        action='append',
+        default=[],
+        metavar='path/url',
+        help=('Install a project in editable mode (i.e. setuptools '
+              '"develop mode") from a local project path or a VCS url.'),
+    )
+
+
+src = partial(
+    Option,
+    '--src', '--source', '--source-dir', '--source-directory',
+    dest='src_dir',
+    metavar='dir',
+    default=src_prefix,
+    help='Directory to check out editable projects into. '
+    'The default in a virtualenv is "<venv path>/src". '
+    'The default for global installs is "<current dir>/src".'
+)  # type: Callable[..., Option]
+
+
+def _get_format_control(values, option):
+    # type: (Values, Option) -> Any
+    """Get a format_control object."""
+    return getattr(values, option.dest)
+
+
+def _handle_no_binary(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    existing = _get_format_control(parser.values, option)
+    FormatControl.handle_mutual_excludes(
+        value, existing.no_binary, existing.only_binary,
+    )
+
+
+def _handle_only_binary(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    existing = _get_format_control(parser.values, option)
+    FormatControl.handle_mutual_excludes(
+        value, existing.only_binary, existing.no_binary,
+    )
+
+
+def no_binary():
+    # type: () -> Option
+    format_control = FormatControl(set(), set())
+    return Option(
+        "--no-binary", dest="format_control", action="callback",
+        callback=_handle_no_binary, type="str",
+        default=format_control,
+        help="Do not use binary packages. Can be supplied multiple times, and "
+             "each time adds to the existing value. Accepts either :all: to "
+             "disable all binary packages, :none: to empty the set, or one or "
+             "more package names with commas between them. Note that some "
+             "packages are tricky to compile and may fail to install when "
+             "this option is used on them.",
+    )
+
+
+def only_binary():
+    # type: () -> Option
+    format_control = FormatControl(set(), set())
+    return Option(
+        "--only-binary", dest="format_control", action="callback",
+        callback=_handle_only_binary, type="str",
+        default=format_control,
+        help="Do not use source packages. Can be supplied multiple times, and "
+             "each time adds to the existing value. Accepts either :all: to "
+             "disable all source packages, :none: to empty the set, or one or "
+             "more package names with commas between them. Packages without "
+             "binary distributions will fail to install when this option is "
+             "used on them.",
+    )
+
+
+platform = partial(
+    Option,
+    '--platform',
+    dest='platform',
+    metavar='platform',
+    default=None,
+    help=("Only use wheels compatible with <platform>. "
+          "Defaults to the platform of the running system."),
+)  # type: Callable[..., Option]
+
+
+python_version = partial(
+    Option,
+    '--python-version',
+    dest='python_version',
+    metavar='python_version',
+    default=None,
+    help=("Only use wheels compatible with Python "
+          "interpreter version <version>. If not specified, then the "
+          "current system interpreter minor version is used. A major "
+          "version (e.g. '2') can be specified to match all "
+          "minor revs of that major version.  A minor version "
+          "(e.g. '34') can also be specified."),
+)  # type: Callable[..., Option]
+
+
+implementation = partial(
+    Option,
+    '--implementation',
+    dest='implementation',
+    metavar='implementation',
+    default=None,
+    help=("Only use wheels compatible with Python "
+          "implementation <implementation>, e.g. 'pp', 'jy', 'cp', "
+          " or 'ip'. If not specified, then the current "
+          "interpreter implementation is used.  Use 'py' to force "
+          "implementation-agnostic wheels."),
+)  # type: Callable[..., Option]
+
+
+abi = partial(
+    Option,
+    '--abi',
+    dest='abi',
+    metavar='abi',
+    default=None,
+    help=("Only use wheels compatible with Python "
+          "abi <abi>, e.g. 'pypy_41'.  If not specified, then the "
+          "current interpreter abi tag is used.  Generally "
+          "you will need to specify --implementation, "
+          "--platform, and --python-version when using "
+          "this option."),
+)  # type: Callable[..., Option]
+
+
+def prefer_binary():
+    # type: () -> Option
+    return Option(
+        "--prefer-binary",
+        dest="prefer_binary",
+        action="store_true",
+        default=False,
+        help="Prefer older binary packages over newer source packages."
+    )
+
+
+cache_dir = partial(
+    Option,
+    "--cache-dir",
+    dest="cache_dir",
+    default=USER_CACHE_DIR,
+    metavar="dir",
+    help="Store the cache data in <dir>."
+)  # type: Callable[..., Option]
+
+
+def no_cache_dir_callback(option, opt, value, parser):
+    """
+    Process a value provided for the --no-cache-dir option.
+
+    This is an optparse.Option callback for the --no-cache-dir option.
+    """
+    # The value argument will be None if --no-cache-dir is passed via the
+    # command-line, since the option doesn't accept arguments.  However,
+    # the value can be non-None if the option is triggered e.g. by an
+    # environment variable, like PIP_NO_CACHE_DIR=true.
+    if value is not None:
+        # Then parse the string value to get argument error-checking.
+        try:
+            strtobool(value)
+        except ValueError as exc:
+            raise_option_error(parser, option=option, msg=str(exc))
+
+    # Originally, setting PIP_NO_CACHE_DIR to a value that strtobool()
+    # converted to 0 (like "false" or "no") caused cache_dir to be disabled
+    # rather than enabled (logic would say the latter).  Thus, we disable
+    # the cache directory not just on values that parse to True, but (for
+    # backwards compatibility reasons) also on values that parse to False.
+    # In other words, always set it to False if the option is provided in
+    # some (valid) form.
+    parser.values.cache_dir = False
+
+
+no_cache = partial(
+    Option,
+    "--no-cache-dir",
+    dest="cache_dir",
+    action="callback",
+    callback=no_cache_dir_callback,
+    help="Disable the cache.",
+)  # type: Callable[..., Option]
+
+no_deps = partial(
+    Option,
+    '--no-deps', '--no-dependencies',
+    dest='ignore_dependencies',
+    action='store_true',
+    default=False,
+    help="Don't install package dependencies.",
+)  # type: Callable[..., Option]
+
+build_dir = partial(
+    Option,
+    '-b', '--build', '--build-dir', '--build-directory',
+    dest='build_dir',
+    metavar='dir',
+    help='Directory to unpack packages into and build in. Note that '
+         'an initial build still takes place in a temporary directory. '
+         'The location of temporary directories can be controlled by setting '
+         'the TMPDIR environment variable (TEMP on Windows) appropriately. '
+         'When passed, build directories are not cleaned in case of failures.'
+)  # type: Callable[..., Option]
+
+ignore_requires_python = partial(
+    Option,
+    '--ignore-requires-python',
+    dest='ignore_requires_python',
+    action='store_true',
+    help='Ignore the Requires-Python information.'
+)  # type: Callable[..., Option]
+
+no_build_isolation = partial(
+    Option,
+    '--no-build-isolation',
+    dest='build_isolation',
+    action='store_false',
+    default=True,
+    help='Disable isolation when building a modern source distribution. '
+         'Build dependencies specified by PEP 518 must be already installed '
+         'if this option is used.'
+)  # type: Callable[..., Option]
+
+
+def no_use_pep517_callback(option, opt, value, parser):
+    """
+    Process a value provided for the --no-use-pep517 option.
+
+    This is an optparse.Option callback for the no_use_pep517 option.
+    """
+    # Since --no-use-pep517 doesn't accept arguments, the value argument
+    # will be None if --no-use-pep517 is passed via the command-line.
+    # However, the value can be non-None if the option is triggered e.g.
+    # by an environment variable, for example "PIP_NO_USE_PEP517=true".
+    if value is not None:
+        msg = """A value was passed for --no-use-pep517,
+        probably using either the PIP_NO_USE_PEP517 environment variable
+        or the "no-use-pep517" config file option. Use an appropriate value
+        of the PIP_USE_PEP517 environment variable or the "use-pep517"
+        config file option instead.
+        """
+        raise_option_error(parser, option=option, msg=msg)
+
+    # Otherwise, --no-use-pep517 was passed via the command-line.
+    parser.values.use_pep517 = False
+
+
+use_pep517 = partial(
+    Option,
+    '--use-pep517',
+    dest='use_pep517',
+    action='store_true',
+    default=None,
+    help='Use PEP 517 for building source distributions '
+         '(use --no-use-pep517 to force legacy behaviour).'
+)  # type: Any
+
+no_use_pep517 = partial(
+    Option,
+    '--no-use-pep517',
+    dest='use_pep517',
+    action='callback',
+    callback=no_use_pep517_callback,
+    default=None,
+    help=SUPPRESS_HELP
+)  # type: Any
+
+install_options = partial(
+    Option,
+    '--install-option',
+    dest='install_options',
+    action='append',
+    metavar='options',
+    help="Extra arguments to be supplied to the setup.py install "
+         "command (use like --install-option=\"--install-scripts=/usr/local/"
+         "bin\"). Use multiple --install-option options to pass multiple "
+         "options to setup.py install. If you are using an option with a "
+         "directory path, be sure to use absolute path.",
+)  # type: Callable[..., Option]
+
+global_options = partial(
+    Option,
+    '--global-option',
+    dest='global_options',
+    action='append',
+    metavar='options',
+    help="Extra global options to be supplied to the setup.py "
+         "call before the install command.",
+)  # type: Callable[..., Option]
+
+no_clean = partial(
+    Option,
+    '--no-clean',
+    action='store_true',
+    default=False,
+    help="Don't clean up build directories."
+)  # type: Callable[..., Option]
+
+pre = partial(
+    Option,
+    '--pre',
+    action='store_true',
+    default=False,
+    help="Include pre-release and development versions. By default, "
+         "pip only finds stable versions.",
+)  # type: Callable[..., Option]
+
+disable_pip_version_check = partial(
+    Option,
+    "--disable-pip-version-check",
+    dest="disable_pip_version_check",
+    action="store_true",
+    default=False,
+    help="Don't periodically check PyPI to determine whether a new version "
+         "of pip is available for download. Implied with --no-index.",
+)  # type: Callable[..., Option]
+
+
+# Deprecated, Remove later
+always_unzip = partial(
+    Option,
+    '-Z', '--always-unzip',
+    dest='always_unzip',
+    action='store_true',
+    help=SUPPRESS_HELP,
+)  # type: Callable[..., Option]
+
+
+def _merge_hash(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    """Given a value spelled "algo:digest", append the digest to a list
+    pointed to in a dict by the algo name."""
+    if not parser.values.hashes:
+        parser.values.hashes = {}  # type: ignore
+    try:
+        algo, digest = value.split(':', 1)
+    except ValueError:
+        parser.error('Arguments to %s must be a hash name '
+                     'followed by a value, like --hash=sha256:abcde...' %
+                     opt_str)
+    if algo not in STRONG_HASHES:
+        parser.error('Allowed hash algorithms for %s are %s.' %
+                     (opt_str, ', '.join(STRONG_HASHES)))
+    parser.values.hashes.setdefault(algo, []).append(digest)
+
+
+hash = partial(
+    Option,
+    '--hash',
+    # Hash values eventually end up in InstallRequirement.hashes due to
+    # __dict__ copying in process_line().
+    dest='hashes',
+    action='callback',
+    callback=_merge_hash,
+    type='string',
+    help="Verify that the package's archive matches this "
+         'hash before installing. Example: --hash=sha256:abcdef...',
+)  # type: Callable[..., Option]
+
+
+require_hashes = partial(
+    Option,
+    '--require-hashes',
+    dest='require_hashes',
+    action='store_true',
+    default=False,
+    help='Require a hash to check each requirement against, for '
+         'repeatable installs. This option is implied when any package in a '
+         'requirements file has a --hash option.',
+)  # type: Callable[..., Option]
+
+
+##########
+# groups #
+##########
+
+general_group = {
+    'name': 'General Options',
+    'options': [
+        help_,
+        isolated_mode,
+        require_virtualenv,
+        verbose,
+        version,
+        quiet,
+        log,
+        no_input,
+        proxy,
+        retries,
+        timeout,
+        skip_requirements_regex,
+        exists_action,
+        trusted_host,
+        cert,
+        client_cert,
+        cache_dir,
+        no_cache,
+        disable_pip_version_check,
+        no_color,
+    ]
+}  # type: Dict[str, Any]
+
+index_group = {
+    'name': 'Package Index Options',
+    'options': [
+        index_url,
+        extra_index_url,
+        no_index,
+        find_links,
+    ]
+}  # type: Dict[str, Any]
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/main_parser.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/main_parser.py
new file mode 100644
index 0000000..b17c749
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/main_parser.py
@@ -0,0 +1,104 @@
+"""A single place for constructing and exposing the main parser
+"""
+
+import os
+import sys
+
+from pip import __version__
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.parser import (
+    ConfigOptionParser, UpdatingDefaultsHelpFormatter,
+)
+from pip._internal.commands import (
+    commands_dict, get_similar_commands, get_summaries,
+)
+from pip._internal.exceptions import CommandError
+from pip._internal.utils.misc import get_prog
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Tuple, List  # noqa: F401
+
+
+__all__ = ["create_main_parser", "parse_command"]
+
+
+def create_main_parser():
+    # type: () -> ConfigOptionParser
+    """Creates and returns the main parser for pip's CLI
+    """
+
+    parser_kw = {
+        'usage': '\n%prog <command> [options]',
+        'add_help_option': False,
+        'formatter': UpdatingDefaultsHelpFormatter(),
+        'name': 'global',
+        'prog': get_prog(),
+    }
+
+    parser = ConfigOptionParser(**parser_kw)
+    parser.disable_interspersed_args()
+
+    pip_pkg_dir = os.path.abspath(os.path.join(
+        os.path.dirname(__file__), "..", "..",
+    ))
+    parser.version = 'pip %s from %s (python %s)' % (
+        __version__, pip_pkg_dir, sys.version[:3],
+    )
+
+    # add the general options
+    gen_opts = cmdoptions.make_option_group(cmdoptions.general_group, parser)
+    parser.add_option_group(gen_opts)
+
+    # so the help formatter knows
+    parser.main = True  # type: ignore
+
+    # create command listing for description
+    command_summaries = get_summaries()
+    description = [''] + ['%-27s %s' % (i, j) for i, j in command_summaries]
+    parser.description = '\n'.join(description)
+
+    return parser
+
+
+def parse_command(args):
+    # type: (List[str]) -> Tuple[str, List[str]]
+    parser = create_main_parser()
+
+    # Note: parser calls disable_interspersed_args(), so the result of this
+    # call is to split the initial args into the general options before the
+    # subcommand and everything else.
+    # For example:
+    #  args: ['--timeout=5', 'install', '--user', 'INITools']
+    #  general_options: ['--timeout==5']
+    #  args_else: ['install', '--user', 'INITools']
+    general_options, args_else = parser.parse_args(args)
+
+    # --version
+    if general_options.version:
+        sys.stdout.write(parser.version)  # type: ignore
+        sys.stdout.write(os.linesep)
+        sys.exit()
+
+    # pip || pip help -> print_help()
+    if not args_else or (args_else[0] == 'help' and len(args_else) == 1):
+        parser.print_help()
+        sys.exit()
+
+    # the subcommand name
+    cmd_name = args_else[0]
+
+    if cmd_name not in commands_dict:
+        guess = get_similar_commands(cmd_name)
+
+        msg = ['unknown command "%s"' % cmd_name]
+        if guess:
+            msg.append('maybe you meant "%s"' % guess)
+
+        raise CommandError(' - '.join(msg))
+
+    # all the args without the subcommand
+    cmd_args = args[:]
+    cmd_args.remove(cmd_name)
+
+    return cmd_name, cmd_args
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/parser.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/parser.py
new file mode 100644
index 0000000..e1eaac4
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/parser.py
@@ -0,0 +1,261 @@
+"""Base option parser setup"""
+from __future__ import absolute_import
+
+import logging
+import optparse
+import sys
+import textwrap
+from distutils.util import strtobool
+
+from pip._vendor.six import string_types
+
+from pip._internal.cli.status_codes import UNKNOWN_ERROR
+from pip._internal.configuration import Configuration, ConfigurationError
+from pip._internal.utils.compat import get_terminal_size
+
+logger = logging.getLogger(__name__)
+
+
+class PrettyHelpFormatter(optparse.IndentedHelpFormatter):
+    """A prettier/less verbose help formatter for optparse."""
+
+    def __init__(self, *args, **kwargs):
+        # help position must be aligned with __init__.parseopts.description
+        kwargs['max_help_position'] = 30
+        kwargs['indent_increment'] = 1
+        kwargs['width'] = get_terminal_size()[0] - 2
+        optparse.IndentedHelpFormatter.__init__(self, *args, **kwargs)
+
+    def format_option_strings(self, option):
+        return self._format_option_strings(option, ' <%s>', ', ')
+
+    def _format_option_strings(self, option, mvarfmt=' <%s>', optsep=', '):
+        """
+        Return a comma-separated list of option strings and metavars.
+
+        :param option:  tuple of (short opt, long opt), e.g: ('-f', '--format')
+        :param mvarfmt: metavar format string - evaluated as mvarfmt % metavar
+        :param optsep:  separator
+        """
+        opts = []
+
+        if option._short_opts:
+            opts.append(option._short_opts[0])
+        if option._long_opts:
+            opts.append(option._long_opts[0])
+        if len(opts) > 1:
+            opts.insert(1, optsep)
+
+        if option.takes_value():
+            metavar = option.metavar or option.dest.lower()
+            opts.append(mvarfmt % metavar.lower())
+
+        return ''.join(opts)
+
+    def format_heading(self, heading):
+        if heading == 'Options':
+            return ''
+        return heading + ':\n'
+
+    def format_usage(self, usage):
+        """
+        Ensure there is only one newline between usage and the first heading
+        if there is no description.
+        """
+        msg = '\nUsage: %s\n' % self.indent_lines(textwrap.dedent(usage), "  ")
+        return msg
+
+    def format_description(self, description):
+        # leave full control over description to us
+        if description:
+            if hasattr(self.parser, 'main'):
+                label = 'Commands'
+            else:
+                label = 'Description'
+            # some doc strings have initial newlines, some don't
+            description = description.lstrip('\n')
+            # some doc strings have final newlines and spaces, some don't
+            description = description.rstrip()
+            # dedent, then reindent
+            description = self.indent_lines(textwrap.dedent(description), "  ")
+            description = '%s:\n%s\n' % (label, description)
+            return description
+        else:
+            return ''
+
+    def format_epilog(self, epilog):
+        # leave full control over epilog to us
+        if epilog:
+            return epilog
+        else:
+            return ''
+
+    def indent_lines(self, text, indent):
+        new_lines = [indent + line for line in text.split('\n')]
+        return "\n".join(new_lines)
+
+
+class UpdatingDefaultsHelpFormatter(PrettyHelpFormatter):
+    """Custom help formatter for use in ConfigOptionParser.
+
+    This is updates the defaults before expanding them, allowing
+    them to show up correctly in the help listing.
+    """
+
+    def expand_default(self, option):
+        if self.parser is not None:
+            self.parser._update_defaults(self.parser.defaults)
+        return optparse.IndentedHelpFormatter.expand_default(self, option)
+
+
+class CustomOptionParser(optparse.OptionParser):
+
+    def insert_option_group(self, idx, *args, **kwargs):
+        """Insert an OptionGroup at a given position."""
+        group = self.add_option_group(*args, **kwargs)
+
+        self.option_groups.pop()
+        self.option_groups.insert(idx, group)
+
+        return group
+
+    @property
+    def option_list_all(self):
+        """Get a list of all options, including those in option groups."""
+        res = self.option_list[:]
+        for i in self.option_groups:
+            res.extend(i.option_list)
+
+        return res
+
+
+class ConfigOptionParser(CustomOptionParser):
+    """Custom option parser which updates its defaults by checking the
+    configuration files and environmental variables"""
+
+    def __init__(self, *args, **kwargs):
+        self.name = kwargs.pop('name')
+
+        isolated = kwargs.pop("isolated", False)
+        self.config = Configuration(isolated)
+
+        assert self.name
+        optparse.OptionParser.__init__(self, *args, **kwargs)
+
+    def check_default(self, option, key, val):
+        try:
+            return option.check_value(key, val)
+        except optparse.OptionValueError as exc:
+            print("An error occurred during configuration: %s" % exc)
+            sys.exit(3)
+
+    def _get_ordered_configuration_items(self):
+        # Configuration gives keys in an unordered manner. Order them.
+        override_order = ["global", self.name, ":env:"]
+
+        # Pool the options into different groups
+        section_items = {name: [] for name in override_order}
+        for section_key, val in self.config.items():
+            # ignore empty values
+            if not val:
+                logger.debug(
+                    "Ignoring configuration key '%s' as it's value is empty.",
+                    section_key
+                )
+                continue
+
+            section, key = section_key.split(".", 1)
+            if section in override_order:
+                section_items[section].append((key, val))
+
+        # Yield each group in their override order
+        for section in override_order:
+            for key, val in section_items[section]:
+                yield key, val
+
+    def _update_defaults(self, defaults):
+        """Updates the given defaults with values from the config files and
+        the environ. Does a little special handling for certain types of
+        options (lists)."""
+
+        # Accumulate complex default state.
+        self.values = optparse.Values(self.defaults)
+        late_eval = set()
+        # Then set the options with those values
+        for key, val in self._get_ordered_configuration_items():
+            # '--' because configuration supports only long names
+            option = self.get_option('--' + key)
+
+            # Ignore options not present in this parser. E.g. non-globals put
+            # in [global] by users that want them to apply to all applicable
+            # commands.
+            if option is None:
+                continue
+
+            if option.action in ('store_true', 'store_false', 'count'):
+                try:
+                    val = strtobool(val)
+                except ValueError:
+                    error_msg = invalid_config_error_message(
+                        option.action, key, val
+                    )
+                    self.error(error_msg)
+
+            elif option.action == 'append':
+                val = val.split()
+                val = [self.check_default(option, key, v) for v in val]
+            elif option.action == 'callback':
+                late_eval.add(option.dest)
+                opt_str = option.get_opt_string()
+                val = option.convert_value(opt_str, val)
+                # From take_action
+                args = option.callback_args or ()
+                kwargs = option.callback_kwargs or {}
+                option.callback(option, opt_str, val, self, *args, **kwargs)
+            else:
+                val = self.check_default(option, key, val)
+
+            defaults[option.dest] = val
+
+        for key in late_eval:
+            defaults[key] = getattr(self.values, key)
+        self.values = None
+        return defaults
+
+    def get_default_values(self):
+        """Overriding to make updating the defaults after instantiation of
+        the option parser possible, _update_defaults() does the dirty work."""
+        if not self.process_default_values:
+            # Old, pre-Optik 1.5 behaviour.
+            return optparse.Values(self.defaults)
+
+        # Load the configuration, or error out in case of an error
+        try:
+            self.config.load()
+        except ConfigurationError as err:
+            self.exit(UNKNOWN_ERROR, str(err))
+
+        defaults = self._update_defaults(self.defaults.copy())  # ours
+        for option in self._get_all_options():
+            default = defaults.get(option.dest)
+            if isinstance(default, string_types):
+                opt_str = option.get_opt_string()
+                defaults[option.dest] = option.check_value(opt_str, default)
+        return optparse.Values(defaults)
+
+    def error(self, msg):
+        self.print_usage(sys.stderr)
+        self.exit(UNKNOWN_ERROR, "%s\n" % msg)
+
+
+def invalid_config_error_message(action, key, val):
+    """Returns a better error message when invalid configuration option
+    is provided."""
+    if action in ('store_true', 'store_false'):
+        return ("{0} is not a valid value for {1} option, "
+                "please specify a boolean value like yes/no, "
+                "true/false or 1/0 instead.").format(val, key)
+
+    return ("{0} is not a valid value for {1} option, "
+            "please specify a numerical value like 1/0 "
+            "instead.").format(val, key)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/status_codes.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/status_codes.py
new file mode 100644
index 0000000..275360a
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/cli/status_codes.py
@@ -0,0 +1,8 @@
+from __future__ import absolute_import
+
+SUCCESS = 0
+ERROR = 1
+UNKNOWN_ERROR = 2
+VIRTUALENV_NOT_FOUND = 3
+PREVIOUS_BUILD_DIR_ERROR = 4
+NO_MATCHES_FOUND = 23
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/__init__.py
new file mode 100644
index 0000000..c7d1da3
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/__init__.py
@@ -0,0 +1,79 @@
+"""
+Package containing all pip commands
+"""
+from __future__ import absolute_import
+
+from pip._internal.commands.completion import CompletionCommand
+from pip._internal.commands.configuration import ConfigurationCommand
+from pip._internal.commands.download import DownloadCommand
+from pip._internal.commands.freeze import FreezeCommand
+from pip._internal.commands.hash import HashCommand
+from pip._internal.commands.help import HelpCommand
+from pip._internal.commands.list import ListCommand
+from pip._internal.commands.check import CheckCommand
+from pip._internal.commands.search import SearchCommand
+from pip._internal.commands.show import ShowCommand
+from pip._internal.commands.install import InstallCommand
+from pip._internal.commands.uninstall import UninstallCommand
+from pip._internal.commands.wheel import WheelCommand
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import List, Type  # noqa: F401
+    from pip._internal.cli.base_command import Command  # noqa: F401
+
+commands_order = [
+    InstallCommand,
+    DownloadCommand,
+    UninstallCommand,
+    FreezeCommand,
+    ListCommand,
+    ShowCommand,
+    CheckCommand,
+    ConfigurationCommand,
+    SearchCommand,
+    WheelCommand,
+    HashCommand,
+    CompletionCommand,
+    HelpCommand,
+]  # type: List[Type[Command]]
+
+commands_dict = {c.name: c for c in commands_order}
+
+
+def get_summaries(ordered=True):
+    """Yields sorted (command name, command summary) tuples."""
+
+    if ordered:
+        cmditems = _sort_commands(commands_dict, commands_order)
+    else:
+        cmditems = commands_dict.items()
+
+    for name, command_class in cmditems:
+        yield (name, command_class.summary)
+
+
+def get_similar_commands(name):
+    """Command name auto-correct."""
+    from difflib import get_close_matches
+
+    name = name.lower()
+
+    close_commands = get_close_matches(name, commands_dict.keys())
+
+    if close_commands:
+        return close_commands[0]
+    else:
+        return False
+
+
+def _sort_commands(cmddict, order):
+    def keyfn(key):
+        try:
+            return order.index(key[1])
+        except ValueError:
+            # unordered items should come last
+            return 0xff
+
+    return sorted(cmddict.items(), key=keyfn)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/check.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/check.py
new file mode 100644
index 0000000..801cecc
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/check.py
@@ -0,0 +1,41 @@
+import logging
+
+from pip._internal.cli.base_command import Command
+from pip._internal.operations.check import (
+    check_package_set, create_package_set_from_installed,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class CheckCommand(Command):
+    """Verify installed packages have compatible dependencies."""
+    name = 'check'
+    usage = """
+      %prog [options]"""
+    summary = 'Verify installed packages have compatible dependencies.'
+
+    def run(self, options, args):
+        package_set, parsing_probs = create_package_set_from_installed()
+        missing, conflicting = check_package_set(package_set)
+
+        for project_name in missing:
+            version = package_set[project_name].version
+            for dependency in missing[project_name]:
+                logger.info(
+                    "%s %s requires %s, which is not installed.",
+                    project_name, version, dependency[0],
+                )
+
+        for project_name in conflicting:
+            version = package_set[project_name].version
+            for dep_name, dep_version, req in conflicting[project_name]:
+                logger.info(
+                    "%s %s has requirement %s, but you have %s %s.",
+                    project_name, version, req, dep_name, dep_version,
+                )
+
+        if missing or conflicting or parsing_probs:
+            return 1
+        else:
+            logger.info("No broken requirements found.")
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/completion.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/completion.py
new file mode 100644
index 0000000..2fcdd39
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/completion.py
@@ -0,0 +1,94 @@
+from __future__ import absolute_import
+
+import sys
+import textwrap
+
+from pip._internal.cli.base_command import Command
+from pip._internal.utils.misc import get_prog
+
+BASE_COMPLETION = """
+# pip %(shell)s completion start%(script)s# pip %(shell)s completion end
+"""
+
+COMPLETION_SCRIPTS = {
+    'bash': """
+        _pip_completion()
+        {
+            COMPREPLY=( $( COMP_WORDS="${COMP_WORDS[*]}" \\
+                           COMP_CWORD=$COMP_CWORD \\
+                           PIP_AUTO_COMPLETE=1 $1 ) )
+        }
+        complete -o default -F _pip_completion %(prog)s
+    """,
+    'zsh': """
+        function _pip_completion {
+          local words cword
+          read -Ac words
+          read -cn cword
+          reply=( $( COMP_WORDS="$words[*]" \\
+                     COMP_CWORD=$(( cword-1 )) \\
+                     PIP_AUTO_COMPLETE=1 $words[1] ) )
+        }
+        compctl -K _pip_completion %(prog)s
+    """,
+    'fish': """
+        function __fish_complete_pip
+            set -lx COMP_WORDS (commandline -o) ""
+            set -lx COMP_CWORD ( \\
+                math (contains -i -- (commandline -t) $COMP_WORDS)-1 \\
+            )
+            set -lx PIP_AUTO_COMPLETE 1
+            string split \\  -- (eval $COMP_WORDS[1])
+        end
+        complete -fa "(__fish_complete_pip)" -c %(prog)s
+    """,
+}
+
+
+class CompletionCommand(Command):
+    """A helper command to be used for command completion."""
+    name = 'completion'
+    summary = 'A helper command used for command completion.'
+    ignore_require_venv = True
+
+    def __init__(self, *args, **kw):
+        super(CompletionCommand, self).__init__(*args, **kw)
+
+        cmd_opts = self.cmd_opts
+
+        cmd_opts.add_option(
+            '--bash', '-b',
+            action='store_const',
+            const='bash',
+            dest='shell',
+            help='Emit completion code for bash')
+        cmd_opts.add_option(
+            '--zsh', '-z',
+            action='store_const',
+            const='zsh',
+            dest='shell',
+            help='Emit completion code for zsh')
+        cmd_opts.add_option(
+            '--fish', '-f',
+            action='store_const',
+            const='fish',
+            dest='shell',
+            help='Emit completion code for fish')
+
+        self.parser.insert_option_group(0, cmd_opts)
+
+    def run(self, options, args):
+        """Prints the completion code of the given shell"""
+        shells = COMPLETION_SCRIPTS.keys()
+        shell_options = ['--' + shell for shell in sorted(shells)]
+        if options.shell in shells:
+            script = textwrap.dedent(
+                COMPLETION_SCRIPTS.get(options.shell, '') % {
+                    'prog': get_prog(),
+                }
+            )
+            print(BASE_COMPLETION % {'script': script, 'shell': options.shell})
+        else:
+            sys.stderr.write(
+                'ERROR: You must pass %s\n' % ' or '.join(shell_options)
+            )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/configuration.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/configuration.py
new file mode 100644
index 0000000..826c08d
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/configuration.py
@@ -0,0 +1,227 @@
+import logging
+import os
+import subprocess
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.status_codes import ERROR, SUCCESS
+from pip._internal.configuration import Configuration, kinds
+from pip._internal.exceptions import PipError
+from pip._internal.locations import venv_config_file
+from pip._internal.utils.misc import get_prog
+
+logger = logging.getLogger(__name__)
+
+
+class ConfigurationCommand(Command):
+    """Manage local and global configuration.
+
+        Subcommands:
+
+        list: List the active configuration (or from the file specified)
+        edit: Edit the configuration file in an editor
+        get: Get the value associated with name
+        set: Set the name=value
+        unset: Unset the value associated with name
+
+        If none of --user, --global and --venv are passed, a virtual
+        environment configuration file is used if one is active and the file
+        exists. Otherwise, all modifications happen on the to the user file by
+        default.
+    """
+
+    name = 'config'
+    usage = """
+        %prog [<file-option>] list
+        %prog [<file-option>] [--editor <editor-path>] edit
+
+        %prog [<file-option>] get name
+        %prog [<file-option>] set name value
+        %prog [<file-option>] unset name
+    """
+
+    summary = "Manage local and global configuration."
+
+    def __init__(self, *args, **kwargs):
+        super(ConfigurationCommand, self).__init__(*args, **kwargs)
+
+        self.configuration = None
+
+        self.cmd_opts.add_option(
+            '--editor',
+            dest='editor',
+            action='store',
+            default=None,
+            help=(
+                'Editor to use to edit the file. Uses VISUAL or EDITOR '
+                'environment variables if not provided.'
+            )
+        )
+
+        self.cmd_opts.add_option(
+            '--global',
+            dest='global_file',
+            action='store_true',
+            default=False,
+            help='Use the system-wide configuration file only'
+        )
+
+        self.cmd_opts.add_option(
+            '--user',
+            dest='user_file',
+            action='store_true',
+            default=False,
+            help='Use the user configuration file only'
+        )
+
+        self.cmd_opts.add_option(
+            '--venv',
+            dest='venv_file',
+            action='store_true',
+            default=False,
+            help='Use the virtualenv configuration file only'
+        )
+
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        handlers = {
+            "list": self.list_values,
+            "edit": self.open_in_editor,
+            "get": self.get_name,
+            "set": self.set_name_value,
+            "unset": self.unset_name
+        }
+
+        # Determine action
+        if not args or args[0] not in handlers:
+            logger.error("Need an action ({}) to perform.".format(
+                ", ".join(sorted(handlers)))
+            )
+            return ERROR
+
+        action = args[0]
+
+        # Determine which configuration files are to be loaded
+        #    Depends on whether the command is modifying.
+        try:
+            load_only = self._determine_file(
+                options, need_value=(action in ["get", "set", "unset", "edit"])
+            )
+        except PipError as e:
+            logger.error(e.args[0])
+            return ERROR
+
+        # Load a new configuration
+        self.configuration = Configuration(
+            isolated=options.isolated_mode, load_only=load_only
+        )
+        self.configuration.load()
+
+        # Error handling happens here, not in the action-handlers.
+        try:
+            handlers[action](options, args[1:])
+        except PipError as e:
+            logger.error(e.args[0])
+            return ERROR
+
+        return SUCCESS
+
+    def _determine_file(self, options, need_value):
+        file_options = {
+            kinds.USER: options.user_file,
+            kinds.GLOBAL: options.global_file,
+            kinds.VENV: options.venv_file
+        }
+
+        if sum(file_options.values()) == 0:
+            if not need_value:
+                return None
+            # Default to user, unless there's a virtualenv file.
+            elif os.path.exists(venv_config_file):
+                return kinds.VENV
+            else:
+                return kinds.USER
+        elif sum(file_options.values()) == 1:
+            # There's probably a better expression for this.
+            return [key for key in file_options if file_options[key]][0]
+
+        raise PipError(
+            "Need exactly one file to operate upon "
+            "(--user, --venv, --global) to perform."
+        )
+
+    def list_values(self, options, args):
+        self._get_n_args(args, "list", n=0)
+
+        for key, value in sorted(self.configuration.items()):
+            logger.info("%s=%r", key, value)
+
+    def get_name(self, options, args):
+        key = self._get_n_args(args, "get [name]", n=1)
+        value = self.configuration.get_value(key)
+
+        logger.info("%s", value)
+
+    def set_name_value(self, options, args):
+        key, value = self._get_n_args(args, "set [name] [value]", n=2)
+        self.configuration.set_value(key, value)
+
+        self._save_configuration()
+
+    def unset_name(self, options, args):
+        key = self._get_n_args(args, "unset [name]", n=1)
+        self.configuration.unset_value(key)
+
+        self._save_configuration()
+
+    def open_in_editor(self, options, args):
+        editor = self._determine_editor(options)
+
+        fname = self.configuration.get_file_to_edit()
+        if fname is None:
+            raise PipError("Could not determine appropriate file.")
+
+        try:
+            subprocess.check_call([editor, fname])
+        except subprocess.CalledProcessError as e:
+            raise PipError(
+                "Editor Subprocess exited with exit code {}"
+                .format(e.returncode)
+            )
+
+    def _get_n_args(self, args, example, n):
+        """Helper to make sure the command got the right number of arguments
+        """
+        if len(args) != n:
+            msg = (
+                'Got unexpected number of arguments, expected {}. '
+                '(example: "{} config {}")'
+            ).format(n, get_prog(), example)
+            raise PipError(msg)
+
+        if n == 1:
+            return args[0]
+        else:
+            return args
+
+    def _save_configuration(self):
+        # We successfully ran a modifying command. Need to save the
+        # configuration.
+        try:
+            self.configuration.save()
+        except Exception:
+            logger.error(
+                "Unable to save configuration. Please report this as a bug.",
+                exc_info=1
+            )
+            raise PipError("Internal Error.")
+
+    def _determine_editor(self, options):
+        if options.editor is not None:
+            return options.editor
+        elif "VISUAL" in os.environ:
+            return os.environ["VISUAL"]
+        elif "EDITOR" in os.environ:
+            return os.environ["EDITOR"]
+        else:
+            raise PipError("Could not determine editor to use.")
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/download.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/download.py
new file mode 100644
index 0000000..a57e4bc
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/download.py
@@ -0,0 +1,176 @@
+from __future__ import absolute_import
+
+import logging
+import os
+
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.base_command import RequirementCommand
+from pip._internal.operations.prepare import RequirementPreparer
+from pip._internal.req import RequirementSet
+from pip._internal.req.req_tracker import RequirementTracker
+from pip._internal.resolve import Resolver
+from pip._internal.utils.filesystem import check_path_owner
+from pip._internal.utils.misc import ensure_dir, normalize_path
+from pip._internal.utils.temp_dir import TempDirectory
+
+logger = logging.getLogger(__name__)
+
+
+class DownloadCommand(RequirementCommand):
+    """
+    Download packages from:
+
+    - PyPI (and other indexes) using requirement specifiers.
+    - VCS project urls.
+    - Local project directories.
+    - Local or remote source archives.
+
+    pip also supports downloading from "requirements files", which provide
+    an easy way to specify a whole environment to be downloaded.
+    """
+    name = 'download'
+
+    usage = """
+      %prog [options] <requirement specifier> [package-index-options] ...
+      %prog [options] -r <requirements file> [package-index-options] ...
+      %prog [options] <vcs project url> ...
+      %prog [options] <local project path> ...
+      %prog [options] <archive url/path> ..."""
+
+    summary = 'Download packages.'
+
+    def __init__(self, *args, **kw):
+        super(DownloadCommand, self).__init__(*args, **kw)
+
+        cmd_opts = self.cmd_opts
+
+        cmd_opts.add_option(cmdoptions.constraints())
+        cmd_opts.add_option(cmdoptions.requirements())
+        cmd_opts.add_option(cmdoptions.build_dir())
+        cmd_opts.add_option(cmdoptions.no_deps())
+        cmd_opts.add_option(cmdoptions.global_options())
+        cmd_opts.add_option(cmdoptions.no_binary())
+        cmd_opts.add_option(cmdoptions.only_binary())
+        cmd_opts.add_option(cmdoptions.prefer_binary())
+        cmd_opts.add_option(cmdoptions.src())
+        cmd_opts.add_option(cmdoptions.pre())
+        cmd_opts.add_option(cmdoptions.no_clean())
+        cmd_opts.add_option(cmdoptions.require_hashes())
+        cmd_opts.add_option(cmdoptions.progress_bar())
+        cmd_opts.add_option(cmdoptions.no_build_isolation())
+        cmd_opts.add_option(cmdoptions.use_pep517())
+        cmd_opts.add_option(cmdoptions.no_use_pep517())
+
+        cmd_opts.add_option(
+            '-d', '--dest', '--destination-dir', '--destination-directory',
+            dest='download_dir',
+            metavar='dir',
+            default=os.curdir,
+            help=("Download packages into <dir>."),
+        )
+
+        cmd_opts.add_option(cmdoptions.platform())
+        cmd_opts.add_option(cmdoptions.python_version())
+        cmd_opts.add_option(cmdoptions.implementation())
+        cmd_opts.add_option(cmdoptions.abi())
+
+        index_opts = cmdoptions.make_option_group(
+            cmdoptions.index_group,
+            self.parser,
+        )
+
+        self.parser.insert_option_group(0, index_opts)
+        self.parser.insert_option_group(0, cmd_opts)
+
+    def run(self, options, args):
+        options.ignore_installed = True
+        # editable doesn't really make sense for `pip download`, but the bowels
+        # of the RequirementSet code require that property.
+        options.editables = []
+
+        if options.python_version:
+            python_versions = [options.python_version]
+        else:
+            python_versions = None
+
+        cmdoptions.check_dist_restriction(options)
+
+        options.src_dir = os.path.abspath(options.src_dir)
+        options.download_dir = normalize_path(options.download_dir)
+
+        ensure_dir(options.download_dir)
+
+        with self._build_session(options) as session:
+            finder = self._build_package_finder(
+                options=options,
+                session=session,
+                platform=options.platform,
+                python_versions=python_versions,
+                abi=options.abi,
+                implementation=options.implementation,
+            )
+            build_delete = (not (options.no_clean or options.build_dir))
+            if options.cache_dir and not check_path_owner(options.cache_dir):
+                logger.warning(
+                    "The directory '%s' or its parent directory is not owned "
+                    "by the current user and caching wheels has been "
+                    "disabled. check the permissions and owner of that "
+                    "directory. If executing pip with sudo, you may want "
+                    "sudo's -H flag.",
+                    options.cache_dir,
+                )
+                options.cache_dir = None
+
+            with RequirementTracker() as req_tracker, TempDirectory(
+                options.build_dir, delete=build_delete, kind="download"
+            ) as directory:
+
+                requirement_set = RequirementSet(
+                    require_hashes=options.require_hashes,
+                )
+                self.populate_requirement_set(
+                    requirement_set,
+                    args,
+                    options,
+                    finder,
+                    session,
+                    self.name,
+                    None
+                )
+
+                preparer = RequirementPreparer(
+                    build_dir=directory.path,
+                    src_dir=options.src_dir,
+                    download_dir=options.download_dir,
+                    wheel_download_dir=None,
+                    progress_bar=options.progress_bar,
+                    build_isolation=options.build_isolation,
+                    req_tracker=req_tracker,
+                )
+
+                resolver = Resolver(
+                    preparer=preparer,
+                    finder=finder,
+                    session=session,
+                    wheel_cache=None,
+                    use_user_site=False,
+                    upgrade_strategy="to-satisfy-only",
+                    force_reinstall=False,
+                    ignore_dependencies=options.ignore_dependencies,
+                    ignore_requires_python=False,
+                    ignore_installed=True,
+                    isolated=options.isolated_mode,
+                )
+                resolver.resolve(requirement_set)
+
+                downloaded = ' '.join([
+                    req.name for req in requirement_set.successfully_downloaded
+                ])
+                if downloaded:
+                    logger.info('Successfully downloaded %s', downloaded)
+
+                # Clean up
+                if not options.no_clean:
+                    requirement_set.cleanup_files()
+
+        return requirement_set
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/freeze.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/freeze.py
new file mode 100644
index 0000000..dc9c53a
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/freeze.py
@@ -0,0 +1,96 @@
+from __future__ import absolute_import
+
+import sys
+
+from pip._internal.cache import WheelCache
+from pip._internal.cli.base_command import Command
+from pip._internal.models.format_control import FormatControl
+from pip._internal.operations.freeze import freeze
+from pip._internal.utils.compat import stdlib_pkgs
+
+DEV_PKGS = {'pip', 'setuptools', 'distribute', 'wheel'}
+
+
+class FreezeCommand(Command):
+    """
+    Output installed packages in requirements format.
+
+    packages are listed in a case-insensitive sorted order.
+    """
+    name = 'freeze'
+    usage = """
+      %prog [options]"""
+    summary = 'Output installed packages in requirements format.'
+    log_streams = ("ext://sys.stderr", "ext://sys.stderr")
+
+    def __init__(self, *args, **kw):
+        super(FreezeCommand, self).__init__(*args, **kw)
+
+        self.cmd_opts.add_option(
+            '-r', '--requirement',
+            dest='requirements',
+            action='append',
+            default=[],
+            metavar='file',
+            help="Use the order in the given requirements file and its "
+                 "comments when generating output. This option can be "
+                 "used multiple times.")
+        self.cmd_opts.add_option(
+            '-f', '--find-links',
+            dest='find_links',
+            action='append',
+            default=[],
+            metavar='URL',
+            help='URL for finding packages, which will be added to the '
+                 'output.')
+        self.cmd_opts.add_option(
+            '-l', '--local',
+            dest='local',
+            action='store_true',
+            default=False,
+            help='If in a virtualenv that has global access, do not output '
+                 'globally-installed packages.')
+        self.cmd_opts.add_option(
+            '--user',
+            dest='user',
+            action='store_true',
+            default=False,
+            help='Only output packages installed in user-site.')
+        self.cmd_opts.add_option(
+            '--all',
+            dest='freeze_all',
+            action='store_true',
+            help='Do not skip these packages in the output:'
+                 ' %s' % ', '.join(DEV_PKGS))
+        self.cmd_opts.add_option(
+            '--exclude-editable',
+            dest='exclude_editable',
+            action='store_true',
+            help='Exclude editable package from output.')
+
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        format_control = FormatControl(set(), set())
+        wheel_cache = WheelCache(options.cache_dir, format_control)
+        skip = set(stdlib_pkgs)
+        if not options.freeze_all:
+            skip.update(DEV_PKGS)
+
+        freeze_kwargs = dict(
+            requirement=options.requirements,
+            find_links=options.find_links,
+            local_only=options.local,
+            user_only=options.user,
+            skip_regex=options.skip_requirements_regex,
+            isolated=options.isolated_mode,
+            wheel_cache=wheel_cache,
+            skip=skip,
+            exclude_editable=options.exclude_editable,
+        )
+
+        try:
+            for line in freeze(**freeze_kwargs):
+                sys.stdout.write(line + '\n')
+        finally:
+            wheel_cache.cleanup()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/hash.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/hash.py
new file mode 100644
index 0000000..423440e
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/hash.py
@@ -0,0 +1,57 @@
+from __future__ import absolute_import
+
+import hashlib
+import logging
+import sys
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.status_codes import ERROR
+from pip._internal.utils.hashes import FAVORITE_HASH, STRONG_HASHES
+from pip._internal.utils.misc import read_chunks
+
+logger = logging.getLogger(__name__)
+
+
+class HashCommand(Command):
+    """
+    Compute a hash of a local package archive.
+
+    These can be used with --hash in a requirements file to do repeatable
+    installs.
+
+    """
+    name = 'hash'
+    usage = '%prog [options] <file> ...'
+    summary = 'Compute hashes of package archives.'
+    ignore_require_venv = True
+
+    def __init__(self, *args, **kw):
+        super(HashCommand, self).__init__(*args, **kw)
+        self.cmd_opts.add_option(
+            '-a', '--algorithm',
+            dest='algorithm',
+            choices=STRONG_HASHES,
+            action='store',
+            default=FAVORITE_HASH,
+            help='The hash algorithm to use: one of %s' %
+                 ', '.join(STRONG_HASHES))
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        if not args:
+            self.parser.print_usage(sys.stderr)
+            return ERROR
+
+        algorithm = options.algorithm
+        for path in args:
+            logger.info('%s:\n--hash=%s:%s',
+                        path, algorithm, _hash_of_file(path, algorithm))
+
+
+def _hash_of_file(path, algorithm):
+    """Return the hash digest of a file."""
+    with open(path, 'rb') as archive:
+        hash = hashlib.new(algorithm)
+        for chunk in read_chunks(archive):
+            hash.update(chunk)
+    return hash.hexdigest()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/help.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/help.py
new file mode 100644
index 0000000..49a81cb
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/help.py
@@ -0,0 +1,37 @@
+from __future__ import absolute_import
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.status_codes import SUCCESS
+from pip._internal.exceptions import CommandError
+
+
+class HelpCommand(Command):
+    """Show help for commands"""
+    name = 'help'
+    usage = """
+      %prog <command>"""
+    summary = 'Show help for commands.'
+    ignore_require_venv = True
+
+    def run(self, options, args):
+        from pip._internal.commands import commands_dict, get_similar_commands
+
+        try:
+            # 'pip help' with no args is handled by pip.__init__.parseopt()
+            cmd_name = args[0]  # the command we need help for
+        except IndexError:
+            return SUCCESS
+
+        if cmd_name not in commands_dict:
+            guess = get_similar_commands(cmd_name)
+
+            msg = ['unknown command "%s"' % cmd_name]
+            if guess:
+                msg.append('maybe you meant "%s"' % guess)
+
+            raise CommandError(' - '.join(msg))
+
+        command = commands_dict[cmd_name]()
+        command.parser.print_help()
+
+        return SUCCESS
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/install.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/install.py
new file mode 100644
index 0000000..1c244d2
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/install.py
@@ -0,0 +1,566 @@
+from __future__ import absolute_import
+
+import errno
+import logging
+import operator
+import os
+import shutil
+from optparse import SUPPRESS_HELP
+
+from pip._vendor import pkg_resources
+
+from pip._internal.cache import WheelCache
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.base_command import RequirementCommand
+from pip._internal.cli.status_codes import ERROR
+from pip._internal.exceptions import (
+    CommandError, InstallationError, PreviousBuildDirError,
+)
+from pip._internal.locations import distutils_scheme, virtualenv_no_global
+from pip._internal.operations.check import check_install_conflicts
+from pip._internal.operations.prepare import RequirementPreparer
+from pip._internal.req import RequirementSet, install_given_reqs
+from pip._internal.req.req_tracker import RequirementTracker
+from pip._internal.resolve import Resolver
+from pip._internal.utils.filesystem import check_path_owner
+from pip._internal.utils.misc import (
+    ensure_dir, get_installed_version,
+    protect_pip_from_modification_on_windows,
+)
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.wheel import WheelBuilder
+
+logger = logging.getLogger(__name__)
+
+
+class InstallCommand(RequirementCommand):
+    """
+    Install packages from:
+
+    - PyPI (and other indexes) using requirement specifiers.
+    - VCS project urls.
+    - Local project directories.
+    - Local or remote source archives.
+
+    pip also supports installing from "requirements files", which provide
+    an easy way to specify a whole environment to be installed.
+    """
+    name = 'install'
+
+    usage = """
+      %prog [options] <requirement specifier> [package-index-options] ...
+      %prog [options] -r <requirements file> [package-index-options] ...
+      %prog [options] [-e] <vcs project url> ...
+      %prog [options] [-e] <local project path> ...
+      %prog [options] <archive url/path> ..."""
+
+    summary = 'Install packages.'
+
+    def __init__(self, *args, **kw):
+        super(InstallCommand, self).__init__(*args, **kw)
+
+        cmd_opts = self.cmd_opts
+
+        cmd_opts.add_option(cmdoptions.requirements())
+        cmd_opts.add_option(cmdoptions.constraints())
+        cmd_opts.add_option(cmdoptions.no_deps())
+        cmd_opts.add_option(cmdoptions.pre())
+
+        cmd_opts.add_option(cmdoptions.editable())
+        cmd_opts.add_option(
+            '-t', '--target',
+            dest='target_dir',
+            metavar='dir',
+            default=None,
+            help='Install packages into <dir>. '
+                 'By default this will not replace existing files/folders in '
+                 '<dir>. Use --upgrade to replace existing packages in <dir> '
+                 'with new versions.'
+        )
+        cmd_opts.add_option(cmdoptions.platform())
+        cmd_opts.add_option(cmdoptions.python_version())
+        cmd_opts.add_option(cmdoptions.implementation())
+        cmd_opts.add_option(cmdoptions.abi())
+
+        cmd_opts.add_option(
+            '--user',
+            dest='use_user_site',
+            action='store_true',
+            help="Install to the Python user install directory for your "
+                 "platform. Typically ~/.local/, or %APPDATA%\\Python on "
+                 "Windows. (See the Python documentation for site.USER_BASE "
+                 "for full details.)")
+        cmd_opts.add_option(
+            '--no-user',
+            dest='use_user_site',
+            action='store_false',
+            help=SUPPRESS_HELP)
+        cmd_opts.add_option(
+            '--root',
+            dest='root_path',
+            metavar='dir',
+            default=None,
+            help="Install everything relative to this alternate root "
+                 "directory.")
+        cmd_opts.add_option(
+            '--prefix',
+            dest='prefix_path',
+            metavar='dir',
+            default=None,
+            help="Installation prefix where lib, bin and other top-level "
+                 "folders are placed")
+
+        cmd_opts.add_option(cmdoptions.build_dir())
+
+        cmd_opts.add_option(cmdoptions.src())
+
+        cmd_opts.add_option(
+            '-U', '--upgrade',
+            dest='upgrade',
+            action='store_true',
+            help='Upgrade all specified packages to the newest available '
+                 'version. The handling of dependencies depends on the '
+                 'upgrade-strategy used.'
+        )
+
+        cmd_opts.add_option(
+            '--upgrade-strategy',
+            dest='upgrade_strategy',
+            default='only-if-needed',
+            choices=['only-if-needed', 'eager'],
+            help='Determines how dependency upgrading should be handled '
+                 '[default: %default]. '
+                 '"eager" - dependencies are upgraded regardless of '
+                 'whether the currently installed version satisfies the '
+                 'requirements of the upgraded package(s). '
+                 '"only-if-needed" -  are upgraded only when they do not '
+                 'satisfy the requirements of the upgraded package(s).'
+        )
+
+        cmd_opts.add_option(
+            '--force-reinstall',
+            dest='force_reinstall',
+            action='store_true',
+            help='Reinstall all packages even if they are already '
+                 'up-to-date.')
+
+        cmd_opts.add_option(
+            '-I', '--ignore-installed',
+            dest='ignore_installed',
+            action='store_true',
+            help='Ignore the installed packages (reinstalling instead).')
+
+        cmd_opts.add_option(cmdoptions.ignore_requires_python())
+        cmd_opts.add_option(cmdoptions.no_build_isolation())
+        cmd_opts.add_option(cmdoptions.use_pep517())
+        cmd_opts.add_option(cmdoptions.no_use_pep517())
+
+        cmd_opts.add_option(cmdoptions.install_options())
+        cmd_opts.add_option(cmdoptions.global_options())
+
+        cmd_opts.add_option(
+            "--compile",
+            action="store_true",
+            dest="compile",
+            default=True,
+            help="Compile Python source files to bytecode",
+        )
+
+        cmd_opts.add_option(
+            "--no-compile",
+            action="store_false",
+            dest="compile",
+            help="Do not compile Python source files to bytecode",
+        )
+
+        cmd_opts.add_option(
+            "--no-warn-script-location",
+            action="store_false",
+            dest="warn_script_location",
+            default=True,
+            help="Do not warn when installing scripts outside PATH",
+        )
+        cmd_opts.add_option(
+            "--no-warn-conflicts",
+            action="store_false",
+            dest="warn_about_conflicts",
+            default=True,
+            help="Do not warn about broken dependencies",
+        )
+
+        cmd_opts.add_option(cmdoptions.no_binary())
+        cmd_opts.add_option(cmdoptions.only_binary())
+        cmd_opts.add_option(cmdoptions.prefer_binary())
+        cmd_opts.add_option(cmdoptions.no_clean())
+        cmd_opts.add_option(cmdoptions.require_hashes())
+        cmd_opts.add_option(cmdoptions.progress_bar())
+
+        index_opts = cmdoptions.make_option_group(
+            cmdoptions.index_group,
+            self.parser,
+        )
+
+        self.parser.insert_option_group(0, index_opts)
+        self.parser.insert_option_group(0, cmd_opts)
+
+    def run(self, options, args):
+        cmdoptions.check_install_build_global(options)
+        upgrade_strategy = "to-satisfy-only"
+        if options.upgrade:
+            upgrade_strategy = options.upgrade_strategy
+
+        if options.build_dir:
+            options.build_dir = os.path.abspath(options.build_dir)
+
+        cmdoptions.check_dist_restriction(options, check_target=True)
+
+        if options.python_version:
+            python_versions = [options.python_version]
+        else:
+            python_versions = None
+
+        options.src_dir = os.path.abspath(options.src_dir)
+        install_options = options.install_options or []
+        if options.use_user_site:
+            if options.prefix_path:
+                raise CommandError(
+                    "Can not combine '--user' and '--prefix' as they imply "
+                    "different installation locations"
+                )
+            if virtualenv_no_global():
+                raise InstallationError(
+                    "Can not perform a '--user' install. User site-packages "
+                    "are not visible in this virtualenv."
+                )
+            install_options.append('--user')
+            install_options.append('--prefix=')
+
+        target_temp_dir = TempDirectory(kind="target")
+        if options.target_dir:
+            options.ignore_installed = True
+            options.target_dir = os.path.abspath(options.target_dir)
+            if (os.path.exists(options.target_dir) and not
+                    os.path.isdir(options.target_dir)):
+                raise CommandError(
+                    "Target path exists but is not a directory, will not "
+                    "continue."
+                )
+
+            # Create a target directory for using with the target option
+            target_temp_dir.create()
+            install_options.append('--home=' + target_temp_dir.path)
+
+        global_options = options.global_options or []
+
+        with self._build_session(options) as session:
+            finder = self._build_package_finder(
+                options=options,
+                session=session,
+                platform=options.platform,
+                python_versions=python_versions,
+                abi=options.abi,
+                implementation=options.implementation,
+            )
+            build_delete = (not (options.no_clean or options.build_dir))
+            wheel_cache = WheelCache(options.cache_dir, options.format_control)
+
+            if options.cache_dir and not check_path_owner(options.cache_dir):
+                logger.warning(
+                    "The directory '%s' or its parent directory is not owned "
+                    "by the current user and caching wheels has been "
+                    "disabled. check the permissions and owner of that "
+                    "directory. If executing pip with sudo, you may want "
+                    "sudo's -H flag.",
+                    options.cache_dir,
+                )
+                options.cache_dir = None
+
+            with RequirementTracker() as req_tracker, TempDirectory(
+                options.build_dir, delete=build_delete, kind="install"
+            ) as directory:
+                requirement_set = RequirementSet(
+                    require_hashes=options.require_hashes,
+                    check_supported_wheels=not options.target_dir,
+                )
+
+                try:
+                    self.populate_requirement_set(
+                        requirement_set, args, options, finder, session,
+                        self.name, wheel_cache
+                    )
+                    preparer = RequirementPreparer(
+                        build_dir=directory.path,
+                        src_dir=options.src_dir,
+                        download_dir=None,
+                        wheel_download_dir=None,
+                        progress_bar=options.progress_bar,
+                        build_isolation=options.build_isolation,
+                        req_tracker=req_tracker,
+                    )
+
+                    resolver = Resolver(
+                        preparer=preparer,
+                        finder=finder,
+                        session=session,
+                        wheel_cache=wheel_cache,
+                        use_user_site=options.use_user_site,
+                        upgrade_strategy=upgrade_strategy,
+                        force_reinstall=options.force_reinstall,
+                        ignore_dependencies=options.ignore_dependencies,
+                        ignore_requires_python=options.ignore_requires_python,
+                        ignore_installed=options.ignore_installed,
+                        isolated=options.isolated_mode,
+                        use_pep517=options.use_pep517
+                    )
+                    resolver.resolve(requirement_set)
+
+                    protect_pip_from_modification_on_windows(
+                        modifying_pip=requirement_set.has_requirement("pip")
+                    )
+
+                    # Consider legacy and PEP517-using requirements separately
+                    legacy_requirements = []
+                    pep517_requirements = []
+                    for req in requirement_set.requirements.values():
+                        if req.use_pep517:
+                            pep517_requirements.append(req)
+                        else:
+                            legacy_requirements.append(req)
+
+                    # We don't build wheels for legacy requirements if we
+                    # don't have wheel installed or we don't have a cache dir
+                    try:
+                        import wheel  # noqa: F401
+                        build_legacy = bool(options.cache_dir)
+                    except ImportError:
+                        build_legacy = False
+
+                    wb = WheelBuilder(
+                        finder, preparer, wheel_cache,
+                        build_options=[], global_options=[],
+                    )
+
+                    # Always build PEP 517 requirements
+                    build_failures = wb.build(
+                        pep517_requirements,
+                        session=session, autobuilding=True
+                    )
+
+                    if build_legacy:
+                        # We don't care about failures building legacy
+                        # requirements, as we'll fall through to a direct
+                        # install for those.
+                        wb.build(
+                            legacy_requirements,
+                            session=session, autobuilding=True
+                        )
+
+                    # If we're using PEP 517, we cannot do a direct install
+                    # so we fail here.
+                    if build_failures:
+                        raise InstallationError(
+                            "Could not build wheels for {} which use"
+                            " PEP 517 and cannot be installed directly".format(
+                                ", ".join(r.name for r in build_failures)))
+
+                    to_install = resolver.get_installation_order(
+                        requirement_set
+                    )
+
+                    # Consistency Checking of the package set we're installing.
+                    should_warn_about_conflicts = (
+                        not options.ignore_dependencies and
+                        options.warn_about_conflicts
+                    )
+                    if should_warn_about_conflicts:
+                        self._warn_about_conflicts(to_install)
+
+                    # Don't warn about script install locations if
+                    # --target has been specified
+                    warn_script_location = options.warn_script_location
+                    if options.target_dir:
+                        warn_script_location = False
+
+                    installed = install_given_reqs(
+                        to_install,
+                        install_options,
+                        global_options,
+                        root=options.root_path,
+                        home=target_temp_dir.path,
+                        prefix=options.prefix_path,
+                        pycompile=options.compile,
+                        warn_script_location=warn_script_location,
+                        use_user_site=options.use_user_site,
+                    )
+
+                    lib_locations = get_lib_location_guesses(
+                        user=options.use_user_site,
+                        home=target_temp_dir.path,
+                        root=options.root_path,
+                        prefix=options.prefix_path,
+                        isolated=options.isolated_mode,
+                    )
+                    working_set = pkg_resources.WorkingSet(lib_locations)
+
+                    reqs = sorted(installed, key=operator.attrgetter('name'))
+                    items = []
+                    for req in reqs:
+                        item = req.name
+                        try:
+                            installed_version = get_installed_version(
+                                req.name, working_set=working_set
+                            )
+                            if installed_version:
+                                item += '-' + installed_version
+                        except Exception:
+                            pass
+                        items.append(item)
+                    installed = ' '.join(items)
+                    if installed:
+                        logger.info('Successfully installed %s', installed)
+                except EnvironmentError as error:
+                    show_traceback = (self.verbosity >= 1)
+
+                    message = create_env_error_message(
+                        error, show_traceback, options.use_user_site,
+                    )
+                    logger.error(message, exc_info=show_traceback)
+
+                    return ERROR
+                except PreviousBuildDirError:
+                    options.no_clean = True
+                    raise
+                finally:
+                    # Clean up
+                    if not options.no_clean:
+                        requirement_set.cleanup_files()
+                        wheel_cache.cleanup()
+
+        if options.target_dir:
+            self._handle_target_dir(
+                options.target_dir, target_temp_dir, options.upgrade
+            )
+        return requirement_set
+
+    def _handle_target_dir(self, target_dir, target_temp_dir, upgrade):
+        ensure_dir(target_dir)
+
+        # Checking both purelib and platlib directories for installed
+        # packages to be moved to target directory
+        lib_dir_list = []
+
+        with target_temp_dir:
+            # Checking both purelib and platlib directories for installed
+            # packages to be moved to target directory
+            scheme = distutils_scheme('', home=target_temp_dir.path)
+            purelib_dir = scheme['purelib']
+            platlib_dir = scheme['platlib']
+            data_dir = scheme['data']
+
+            if os.path.exists(purelib_dir):
+                lib_dir_list.append(purelib_dir)
+            if os.path.exists(platlib_dir) and platlib_dir != purelib_dir:
+                lib_dir_list.append(platlib_dir)
+            if os.path.exists(data_dir):
+                lib_dir_list.append(data_dir)
+
+            for lib_dir in lib_dir_list:
+                for item in os.listdir(lib_dir):
+                    if lib_dir == data_dir:
+                        ddir = os.path.join(data_dir, item)
+                        if any(s.startswith(ddir) for s in lib_dir_list[:-1]):
+                            continue
+                    target_item_dir = os.path.join(target_dir, item)
+                    if os.path.exists(target_item_dir):
+                        if not upgrade:
+                            logger.warning(
+                                'Target directory %s already exists. Specify '
+                                '--upgrade to force replacement.',
+                                target_item_dir
+                            )
+                            continue
+                        if os.path.islink(target_item_dir):
+                            logger.warning(
+                                'Target directory %s already exists and is '
+                                'a link. Pip will not automatically replace '
+                                'links, please remove if replacement is '
+                                'desired.',
+                                target_item_dir
+                            )
+                            continue
+                        if os.path.isdir(target_item_dir):
+                            shutil.rmtree(target_item_dir)
+                        else:
+                            os.remove(target_item_dir)
+
+                    shutil.move(
+                        os.path.join(lib_dir, item),
+                        target_item_dir
+                    )
+
+    def _warn_about_conflicts(self, to_install):
+        try:
+            package_set, _dep_info = check_install_conflicts(to_install)
+        except Exception:
+            logger.error("Error checking for conflicts.", exc_info=True)
+            return
+        missing, conflicting = _dep_info
+
+        # NOTE: There is some duplication here from pip check
+        for project_name in missing:
+            version = package_set[project_name][0]
+            for dependency in missing[project_name]:
+                logger.critical(
+                    "%s %s requires %s, which is not installed.",
+                    project_name, version, dependency[1],
+                )
+
+        for project_name in conflicting:
+            version = package_set[project_name][0]
+            for dep_name, dep_version, req in conflicting[project_name]:
+                logger.critical(
+                    "%s %s has requirement %s, but you'll have %s %s which is "
+                    "incompatible.",
+                    project_name, version, req, dep_name, dep_version,
+                )
+
+
+def get_lib_location_guesses(*args, **kwargs):
+    scheme = distutils_scheme('', *args, **kwargs)
+    return [scheme['purelib'], scheme['platlib']]
+
+
+def create_env_error_message(error, show_traceback, using_user_site):
+    """Format an error message for an EnvironmentError
+
+    It may occur anytime during the execution of the install command.
+    """
+    parts = []
+
+    # Mention the error if we are not going to show a traceback
+    parts.append("Could not install packages due to an EnvironmentError")
+    if not show_traceback:
+        parts.append(": ")
+        parts.append(str(error))
+    else:
+        parts.append(".")
+
+    # Spilt the error indication from a helper message (if any)
+    parts[-1] += "\n"
+
+    # Suggest useful actions to the user:
+    #  (1) using user site-packages or (2) verifying the permissions
+    if error.errno == errno.EACCES:
+        user_option_part = "Consider using the `--user` option"
+        permissions_part = "Check the permissions"
+
+        if not using_user_site:
+            parts.extend([
+                user_option_part, " or ",
+                permissions_part.lower(),
+            ])
+        else:
+            parts.append(permissions_part)
+        parts.append(".\n")
+
+    return "".join(parts).strip() + "\n"
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/list.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/list.py
new file mode 100644
index 0000000..a640274
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/list.py
@@ -0,0 +1,301 @@
+from __future__ import absolute_import
+
+import json
+import logging
+
+from pip._vendor import six
+from pip._vendor.six.moves import zip_longest
+
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.base_command import Command
+from pip._internal.exceptions import CommandError
+from pip._internal.index import PackageFinder
+from pip._internal.utils.misc import (
+    dist_is_editable, get_installed_distributions,
+)
+from pip._internal.utils.packaging import get_installer
+
+logger = logging.getLogger(__name__)
+
+
+class ListCommand(Command):
+    """
+    List installed packages, including editables.
+
+    Packages are listed in a case-insensitive sorted order.
+    """
+    name = 'list'
+    usage = """
+      %prog [options]"""
+    summary = 'List installed packages.'
+
+    def __init__(self, *args, **kw):
+        super(ListCommand, self).__init__(*args, **kw)
+
+        cmd_opts = self.cmd_opts
+
+        cmd_opts.add_option(
+            '-o', '--outdated',
+            action='store_true',
+            default=False,
+            help='List outdated packages')
+        cmd_opts.add_option(
+            '-u', '--uptodate',
+            action='store_true',
+            default=False,
+            help='List uptodate packages')
+        cmd_opts.add_option(
+            '-e', '--editable',
+            action='store_true',
+            default=False,
+            help='List editable projects.')
+        cmd_opts.add_option(
+            '-l', '--local',
+            action='store_true',
+            default=False,
+            help=('If in a virtualenv that has global access, do not list '
+                  'globally-installed packages.'),
+        )
+        self.cmd_opts.add_option(
+            '--user',
+            dest='user',
+            action='store_true',
+            default=False,
+            help='Only output packages installed in user-site.')
+
+        cmd_opts.add_option(
+            '--pre',
+            action='store_true',
+            default=False,
+            help=("Include pre-release and development versions. By default, "
+                  "pip only finds stable versions."),
+        )
+
+        cmd_opts.add_option(
+            '--format',
+            action='store',
+            dest='list_format',
+            default="columns",
+            choices=('columns', 'freeze', 'json'),
+            help="Select the output format among: columns (default), freeze, "
+                 "or json",
+        )
+
+        cmd_opts.add_option(
+            '--not-required',
+            action='store_true',
+            dest='not_required',
+            help="List packages that are not dependencies of "
+                 "installed packages.",
+        )
+
+        cmd_opts.add_option(
+            '--exclude-editable',
+            action='store_false',
+            dest='include_editable',
+            help='Exclude editable package from output.',
+        )
+        cmd_opts.add_option(
+            '--include-editable',
+            action='store_true',
+            dest='include_editable',
+            help='Include editable package from output.',
+            default=True,
+        )
+        index_opts = cmdoptions.make_option_group(
+            cmdoptions.index_group, self.parser
+        )
+
+        self.parser.insert_option_group(0, index_opts)
+        self.parser.insert_option_group(0, cmd_opts)
+
+    def _build_package_finder(self, options, index_urls, session):
+        """
+        Create a package finder appropriate to this list command.
+        """
+        return PackageFinder(
+            find_links=options.find_links,
+            index_urls=index_urls,
+            allow_all_prereleases=options.pre,
+            trusted_hosts=options.trusted_hosts,
+            session=session,
+        )
+
+    def run(self, options, args):
+        if options.outdated and options.uptodate:
+            raise CommandError(
+                "Options --outdated and --uptodate cannot be combined.")
+
+        packages = get_installed_distributions(
+            local_only=options.local,
+            user_only=options.user,
+            editables_only=options.editable,
+            include_editables=options.include_editable,
+        )
+
+        # get_not_required must be called firstly in order to find and
+        # filter out all dependencies correctly. Otherwise a package
+        # can't be identified as requirement because some parent packages
+        # could be filtered out before.
+        if options.not_required:
+            packages = self.get_not_required(packages, options)
+
+        if options.outdated:
+            packages = self.get_outdated(packages, options)
+        elif options.uptodate:
+            packages = self.get_uptodate(packages, options)
+
+        self.output_package_listing(packages, options)
+
+    def get_outdated(self, packages, options):
+        return [
+            dist for dist in self.iter_packages_latest_infos(packages, options)
+            if dist.latest_version > dist.parsed_version
+        ]
+
+    def get_uptodate(self, packages, options):
+        return [
+            dist for dist in self.iter_packages_latest_infos(packages, options)
+            if dist.latest_version == dist.parsed_version
+        ]
+
+    def get_not_required(self, packages, options):
+        dep_keys = set()
+        for dist in packages:
+            dep_keys.update(requirement.key for requirement in dist.requires())
+        return {pkg for pkg in packages if pkg.key not in dep_keys}
+
+    def iter_packages_latest_infos(self, packages, options):
+        index_urls = [options.index_url] + options.extra_index_urls
+        if options.no_index:
+            logger.debug('Ignoring indexes: %s', ','.join(index_urls))
+            index_urls = []
+
+        with self._build_session(options) as session:
+            finder = self._build_package_finder(options, index_urls, session)
+
+            for dist in packages:
+                typ = 'unknown'
+                all_candidates = finder.find_all_candidates(dist.key)
+                if not options.pre:
+                    # Remove prereleases
+                    all_candidates = [candidate for candidate in all_candidates
+                                      if not candidate.version.is_prerelease]
+
+                if not all_candidates:
+                    continue
+                best_candidate = max(all_candidates,
+                                     key=finder._candidate_sort_key)
+                remote_version = best_candidate.version
+                if best_candidate.location.is_wheel:
+                    typ = 'wheel'
+                else:
+                    typ = 'sdist'
+                # This is dirty but makes the rest of the code much cleaner
+                dist.latest_version = remote_version
+                dist.latest_filetype = typ
+                yield dist
+
+    def output_package_listing(self, packages, options):
+        packages = sorted(
+            packages,
+            key=lambda dist: dist.project_name.lower(),
+        )
+        if options.list_format == 'columns' and packages:
+            data, header = format_for_columns(packages, options)
+            self.output_package_listing_columns(data, header)
+        elif options.list_format == 'freeze':
+            for dist in packages:
+                if options.verbose >= 1:
+                    logger.info("%s==%s (%s)", dist.project_name,
+                                dist.version, dist.location)
+                else:
+                    logger.info("%s==%s", dist.project_name, dist.version)
+        elif options.list_format == 'json':
+            logger.info(format_for_json(packages, options))
+
+    def output_package_listing_columns(self, data, header):
+        # insert the header first: we need to know the size of column names
+        if len(data) > 0:
+            data.insert(0, header)
+
+        pkg_strings, sizes = tabulate(data)
+
+        # Create and add a separator.
+        if len(data) > 0:
+            pkg_strings.insert(1, " ".join(map(lambda x: '-' * x, sizes)))
+
+        for val in pkg_strings:
+            logger.info(val)
+
+
+def tabulate(vals):
+    # From pfmoore on GitHub:
+    # https://github.com/pypa/pip/issues/3651#issuecomment-216932564
+    assert len(vals) > 0
+
+    sizes = [0] * max(len(x) for x in vals)
+    for row in vals:
+        sizes = [max(s, len(str(c))) for s, c in zip_longest(sizes, row)]
+
+    result = []
+    for row in vals:
+        display = " ".join([str(c).ljust(s) if c is not None else ''
+                            for s, c in zip_longest(sizes, row)])
+        result.append(display)
+
+    return result, sizes
+
+
+def format_for_columns(pkgs, options):
+    """
+    Convert the package data into something usable
+    by output_package_listing_columns.
+    """
+    running_outdated = options.outdated
+    # Adjust the header for the `pip list --outdated` case.
+    if running_outdated:
+        header = ["Package", "Version", "Latest", "Type"]
+    else:
+        header = ["Package", "Version"]
+
+    data = []
+    if options.verbose >= 1 or any(dist_is_editable(x) for x in pkgs):
+        header.append("Location")
+    if options.verbose >= 1:
+        header.append("Installer")
+
+    for proj in pkgs:
+        # if we're working on the 'outdated' list, separate out the
+        # latest_version and type
+        row = [proj.project_name, proj.version]
+
+        if running_outdated:
+            row.append(proj.latest_version)
+            row.append(proj.latest_filetype)
+
+        if options.verbose >= 1 or dist_is_editable(proj):
+            row.append(proj.location)
+        if options.verbose >= 1:
+            row.append(get_installer(proj))
+
+        data.append(row)
+
+    return data, header
+
+
+def format_for_json(packages, options):
+    data = []
+    for dist in packages:
+        info = {
+            'name': dist.project_name,
+            'version': six.text_type(dist.version),
+        }
+        if options.verbose >= 1:
+            info['location'] = dist.location
+            info['installer'] = get_installer(dist)
+        if options.outdated:
+            info['latest_version'] = six.text_type(dist.latest_version)
+            info['latest_filetype'] = dist.latest_filetype
+        data.append(info)
+    return json.dumps(data)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/search.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/search.py
new file mode 100644
index 0000000..c157a31
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/search.py
@@ -0,0 +1,135 @@
+from __future__ import absolute_import
+
+import logging
+import sys
+import textwrap
+from collections import OrderedDict
+
+from pip._vendor import pkg_resources
+from pip._vendor.packaging.version import parse as parse_version
+# NOTE: XMLRPC Client is not annotated in typeshed as on 2017-07-17, which is
+#       why we ignore the type on this import
+from pip._vendor.six.moves import xmlrpc_client  # type: ignore
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.status_codes import NO_MATCHES_FOUND, SUCCESS
+from pip._internal.download import PipXmlrpcTransport
+from pip._internal.exceptions import CommandError
+from pip._internal.models.index import PyPI
+from pip._internal.utils.compat import get_terminal_size
+from pip._internal.utils.logging import indent_log
+
+logger = logging.getLogger(__name__)
+
+
+class SearchCommand(Command):
+    """Search for PyPI packages whose name or summary contains <query>."""
+    name = 'search'
+    usage = """
+      %prog [options] <query>"""
+    summary = 'Search PyPI for packages.'
+    ignore_require_venv = True
+
+    def __init__(self, *args, **kw):
+        super(SearchCommand, self).__init__(*args, **kw)
+        self.cmd_opts.add_option(
+            '-i', '--index',
+            dest='index',
+            metavar='URL',
+            default=PyPI.pypi_url,
+            help='Base URL of Python Package Index (default %default)')
+
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        if not args:
+            raise CommandError('Missing required argument (search query).')
+        query = args
+        pypi_hits = self.search(query, options)
+        hits = transform_hits(pypi_hits)
+
+        terminal_width = None
+        if sys.stdout.isatty():
+            terminal_width = get_terminal_size()[0]
+
+        print_results(hits, terminal_width=terminal_width)
+        if pypi_hits:
+            return SUCCESS
+        return NO_MATCHES_FOUND
+
+    def search(self, query, options):
+        index_url = options.index
+        with self._build_session(options) as session:
+            transport = PipXmlrpcTransport(index_url, session)
+            pypi = xmlrpc_client.ServerProxy(index_url, transport)
+            hits = pypi.search({'name': query, 'summary': query}, 'or')
+            return hits
+
+
+def transform_hits(hits):
+    """
+    The list from pypi is really a list of versions. We want a list of
+    packages with the list of versions stored inline. This converts the
+    list from pypi into one we can use.
+    """
+    packages = OrderedDict()
+    for hit in hits:
+        name = hit['name']
+        summary = hit['summary']
+        version = hit['version']
+
+        if name not in packages.keys():
+            packages[name] = {
+                'name': name,
+                'summary': summary,
+                'versions': [version],
+            }
+        else:
+            packages[name]['versions'].append(version)
+
+            # if this is the highest version, replace summary and score
+            if version == highest_version(packages[name]['versions']):
+                packages[name]['summary'] = summary
+
+    return list(packages.values())
+
+
+def print_results(hits, name_column_width=None, terminal_width=None):
+    if not hits:
+        return
+    if name_column_width is None:
+        name_column_width = max([
+            len(hit['name']) + len(highest_version(hit.get('versions', ['-'])))
+            for hit in hits
+        ]) + 4
+
+    installed_packages = [p.project_name for p in pkg_resources.working_set]
+    for hit in hits:
+        name = hit['name']
+        summary = hit['summary'] or ''
+        latest = highest_version(hit.get('versions', ['-']))
+        if terminal_width is not None:
+            target_width = terminal_width - name_column_width - 5
+            if target_width > 10:
+                # wrap and indent summary to fit terminal
+                summary = textwrap.wrap(summary, target_width)
+                summary = ('\n' + ' ' * (name_column_width + 3)).join(summary)
+
+        line = '%-*s - %s' % (name_column_width,
+                              '%s (%s)' % (name, latest), summary)
+        try:
+            logger.info(line)
+            if name in installed_packages:
+                dist = pkg_resources.get_distribution(name)
+                with indent_log():
+                    if dist.version == latest:
+                        logger.info('INSTALLED: %s (latest)', dist.version)
+                    else:
+                        logger.info('INSTALLED: %s', dist.version)
+                        logger.info('LATEST:    %s', latest)
+        except UnicodeEncodeError:
+            pass
+
+
+def highest_version(versions):
+    return max(versions, key=parse_version)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/show.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/show.py
new file mode 100644
index 0000000..f92c9bc
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/show.py
@@ -0,0 +1,168 @@
+from __future__ import absolute_import
+
+import logging
+import os
+from email.parser import FeedParser  # type: ignore
+
+from pip._vendor import pkg_resources
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.status_codes import ERROR, SUCCESS
+
+logger = logging.getLogger(__name__)
+
+
+class ShowCommand(Command):
+    """
+    Show information about one or more installed packages.
+
+    The output is in RFC-compliant mail header format.
+    """
+    name = 'show'
+    usage = """
+      %prog [options] <package> ..."""
+    summary = 'Show information about installed packages.'
+    ignore_require_venv = True
+
+    def __init__(self, *args, **kw):
+        super(ShowCommand, self).__init__(*args, **kw)
+        self.cmd_opts.add_option(
+            '-f', '--files',
+            dest='files',
+            action='store_true',
+            default=False,
+            help='Show the full list of installed files for each package.')
+
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        if not args:
+            logger.warning('ERROR: Please provide a package name or names.')
+            return ERROR
+        query = args
+
+        results = search_packages_info(query)
+        if not print_results(
+                results, list_files=options.files, verbose=options.verbose):
+            return ERROR
+        return SUCCESS
+
+
+def search_packages_info(query):
+    """
+    Gather details from installed distributions. Print distribution name,
+    version, location, and installed files. Installed files requires a
+    pip generated 'installed-files.txt' in the distributions '.egg-info'
+    directory.
+    """
+    installed = {}
+    for p in pkg_resources.working_set:
+        installed[canonicalize_name(p.project_name)] = p
+
+    query_names = [canonicalize_name(name) for name in query]
+
+    for dist in [installed[pkg] for pkg in query_names if pkg in installed]:
+        package = {
+            'name': dist.project_name,
+            'version': dist.version,
+            'location': dist.location,
+            'requires': [dep.project_name for dep in dist.requires()],
+        }
+        file_list = None
+        metadata = None
+        if isinstance(dist, pkg_resources.DistInfoDistribution):
+            # RECORDs should be part of .dist-info metadatas
+            if dist.has_metadata('RECORD'):
+                lines = dist.get_metadata_lines('RECORD')
+                paths = [l.split(',')[0] for l in lines]
+                paths = [os.path.join(dist.location, p) for p in paths]
+                file_list = [os.path.relpath(p, dist.location) for p in paths]
+
+            if dist.has_metadata('METADATA'):
+                metadata = dist.get_metadata('METADATA')
+        else:
+            # Otherwise use pip's log for .egg-info's
+            if dist.has_metadata('installed-files.txt'):
+                paths = dist.get_metadata_lines('installed-files.txt')
+                paths = [os.path.join(dist.egg_info, p) for p in paths]
+                file_list = [os.path.relpath(p, dist.location) for p in paths]
+
+            if dist.has_metadata('PKG-INFO'):
+                metadata = dist.get_metadata('PKG-INFO')
+
+        if dist.has_metadata('entry_points.txt'):
+            entry_points = dist.get_metadata_lines('entry_points.txt')
+            package['entry_points'] = entry_points
+
+        if dist.has_metadata('INSTALLER'):
+            for line in dist.get_metadata_lines('INSTALLER'):
+                if line.strip():
+                    package['installer'] = line.strip()
+                    break
+
+        # @todo: Should pkg_resources.Distribution have a
+        # `get_pkg_info` method?
+        feed_parser = FeedParser()
+        feed_parser.feed(metadata)
+        pkg_info_dict = feed_parser.close()
+        for key in ('metadata-version', 'summary',
+                    'home-page', 'author', 'author-email', 'license'):
+            package[key] = pkg_info_dict.get(key)
+
+        # It looks like FeedParser cannot deal with repeated headers
+        classifiers = []
+        for line in metadata.splitlines():
+            if line.startswith('Classifier: '):
+                classifiers.append(line[len('Classifier: '):])
+        package['classifiers'] = classifiers
+
+        if file_list:
+            package['files'] = sorted(file_list)
+        yield package
+
+
+def print_results(distributions, list_files=False, verbose=False):
+    """
+    Print the informations from installed distributions found.
+    """
+    results_printed = False
+    for i, dist in enumerate(distributions):
+        results_printed = True
+        if i > 0:
+            logger.info("---")
+
+        name = dist.get('name', '')
+        required_by = [
+            pkg.project_name for pkg in pkg_resources.working_set
+            if name in [required.name for required in pkg.requires()]
+        ]
+
+        logger.info("Name: %s", name)
+        logger.info("Version: %s", dist.get('version', ''))
+        logger.info("Summary: %s", dist.get('summary', ''))
+        logger.info("Home-page: %s", dist.get('home-page', ''))
+        logger.info("Author: %s", dist.get('author', ''))
+        logger.info("Author-email: %s", dist.get('author-email', ''))
+        logger.info("License: %s", dist.get('license', ''))
+        logger.info("Location: %s", dist.get('location', ''))
+        logger.info("Requires: %s", ', '.join(dist.get('requires', [])))
+        logger.info("Required-by: %s", ', '.join(required_by))
+
+        if verbose:
+            logger.info("Metadata-Version: %s",
+                        dist.get('metadata-version', ''))
+            logger.info("Installer: %s", dist.get('installer', ''))
+            logger.info("Classifiers:")
+            for classifier in dist.get('classifiers', []):
+                logger.info("  %s", classifier)
+            logger.info("Entry-points:")
+            for entry in dist.get('entry_points', []):
+                logger.info("  %s", entry.strip())
+        if list_files:
+            logger.info("Files:")
+            for line in dist.get('files', []):
+                logger.info("  %s", line.strip())
+            if "files" not in dist:
+                logger.info("Cannot locate installed-files.txt")
+    return results_printed
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/uninstall.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/uninstall.py
new file mode 100644
index 0000000..0cd6f54
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/uninstall.py
@@ -0,0 +1,78 @@
+from __future__ import absolute_import
+
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.cli.base_command import Command
+from pip._internal.exceptions import InstallationError
+from pip._internal.req import parse_requirements
+from pip._internal.req.constructors import install_req_from_line
+from pip._internal.utils.misc import protect_pip_from_modification_on_windows
+
+
+class UninstallCommand(Command):
+    """
+    Uninstall packages.
+
+    pip is able to uninstall most installed packages. Known exceptions are:
+
+    - Pure distutils packages installed with ``python setup.py install``, which
+      leave behind no metadata to determine what files were installed.
+    - Script wrappers installed by ``python setup.py develop``.
+    """
+    name = 'uninstall'
+    usage = """
+      %prog [options] <package> ...
+      %prog [options] -r <requirements file> ..."""
+    summary = 'Uninstall packages.'
+
+    def __init__(self, *args, **kw):
+        super(UninstallCommand, self).__init__(*args, **kw)
+        self.cmd_opts.add_option(
+            '-r', '--requirement',
+            dest='requirements',
+            action='append',
+            default=[],
+            metavar='file',
+            help='Uninstall all the packages listed in the given requirements '
+                 'file.  This option can be used multiple times.',
+        )
+        self.cmd_opts.add_option(
+            '-y', '--yes',
+            dest='yes',
+            action='store_true',
+            help="Don't ask for confirmation of uninstall deletions.")
+
+        self.parser.insert_option_group(0, self.cmd_opts)
+
+    def run(self, options, args):
+        with self._build_session(options) as session:
+            reqs_to_uninstall = {}
+            for name in args:
+                req = install_req_from_line(
+                    name, isolated=options.isolated_mode,
+                )
+                if req.name:
+                    reqs_to_uninstall[canonicalize_name(req.name)] = req
+            for filename in options.requirements:
+                for req in parse_requirements(
+                        filename,
+                        options=options,
+                        session=session):
+                    if req.name:
+                        reqs_to_uninstall[canonicalize_name(req.name)] = req
+            if not reqs_to_uninstall:
+                raise InstallationError(
+                    'You must give at least one requirement to %(name)s (see '
+                    '"pip help %(name)s")' % dict(name=self.name)
+                )
+
+            protect_pip_from_modification_on_windows(
+                modifying_pip="pip" in reqs_to_uninstall
+            )
+
+            for req in reqs_to_uninstall.values():
+                uninstall_pathset = req.uninstall(
+                    auto_confirm=options.yes, verbose=self.verbosity > 0,
+                )
+                if uninstall_pathset:
+                    uninstall_pathset.commit()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/wheel.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/wheel.py
new file mode 100644
index 0000000..cd72a3d
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/commands/wheel.py
@@ -0,0 +1,186 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+
+import logging
+import os
+
+from pip._internal.cache import WheelCache
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.base_command import RequirementCommand
+from pip._internal.exceptions import CommandError, PreviousBuildDirError
+from pip._internal.operations.prepare import RequirementPreparer
+from pip._internal.req import RequirementSet
+from pip._internal.req.req_tracker import RequirementTracker
+from pip._internal.resolve import Resolver
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.wheel import WheelBuilder
+
+logger = logging.getLogger(__name__)
+
+
+class WheelCommand(RequirementCommand):
+    """
+    Build Wheel archives for your requirements and dependencies.
+
+    Wheel is a built-package format, and offers the advantage of not
+    recompiling your software during every install. For more details, see the
+    wheel docs: https://wheel.readthedocs.io/en/latest/
+
+    Requirements: setuptools>=0.8, and wheel.
+
+    'pip wheel' uses the bdist_wheel setuptools extension from the wheel
+    package to build individual wheels.
+
+    """
+
+    name = 'wheel'
+    usage = """
+      %prog [options] <requirement specifier> ...
+      %prog [options] -r <requirements file> ...
+      %prog [options] [-e] <vcs project url> ...
+      %prog [options] [-e] <local project path> ...
+      %prog [options] <archive url/path> ..."""
+
+    summary = 'Build wheels from your requirements.'
+
+    def __init__(self, *args, **kw):
+        super(WheelCommand, self).__init__(*args, **kw)
+
+        cmd_opts = self.cmd_opts
+
+        cmd_opts.add_option(
+            '-w', '--wheel-dir',
+            dest='wheel_dir',
+            metavar='dir',
+            default=os.curdir,
+            help=("Build wheels into <dir>, where the default is the "
+                  "current working directory."),
+        )
+        cmd_opts.add_option(cmdoptions.no_binary())
+        cmd_opts.add_option(cmdoptions.only_binary())
+        cmd_opts.add_option(cmdoptions.prefer_binary())
+        cmd_opts.add_option(
+            '--build-option',
+            dest='build_options',
+            metavar='options',
+            action='append',
+            help="Extra arguments to be supplied to 'setup.py bdist_wheel'.",
+        )
+        cmd_opts.add_option(cmdoptions.no_build_isolation())
+        cmd_opts.add_option(cmdoptions.use_pep517())
+        cmd_opts.add_option(cmdoptions.no_use_pep517())
+        cmd_opts.add_option(cmdoptions.constraints())
+        cmd_opts.add_option(cmdoptions.editable())
+        cmd_opts.add_option(cmdoptions.requirements())
+        cmd_opts.add_option(cmdoptions.src())
+        cmd_opts.add_option(cmdoptions.ignore_requires_python())
+        cmd_opts.add_option(cmdoptions.no_deps())
+        cmd_opts.add_option(cmdoptions.build_dir())
+        cmd_opts.add_option(cmdoptions.progress_bar())
+
+        cmd_opts.add_option(
+            '--global-option',
+            dest='global_options',
+            action='append',
+            metavar='options',
+            help="Extra global options to be supplied to the setup.py "
+            "call before the 'bdist_wheel' command.")
+
+        cmd_opts.add_option(
+            '--pre',
+            action='store_true',
+            default=False,
+            help=("Include pre-release and development versions. By default, "
+                  "pip only finds stable versions."),
+        )
+
+        cmd_opts.add_option(cmdoptions.no_clean())
+        cmd_opts.add_option(cmdoptions.require_hashes())
+
+        index_opts = cmdoptions.make_option_group(
+            cmdoptions.index_group,
+            self.parser,
+        )
+
+        self.parser.insert_option_group(0, index_opts)
+        self.parser.insert_option_group(0, cmd_opts)
+
+    def run(self, options, args):
+        cmdoptions.check_install_build_global(options)
+
+        index_urls = [options.index_url] + options.extra_index_urls
+        if options.no_index:
+            logger.debug('Ignoring indexes: %s', ','.join(index_urls))
+            index_urls = []
+
+        if options.build_dir:
+            options.build_dir = os.path.abspath(options.build_dir)
+
+        options.src_dir = os.path.abspath(options.src_dir)
+
+        with self._build_session(options) as session:
+            finder = self._build_package_finder(options, session)
+            build_delete = (not (options.no_clean or options.build_dir))
+            wheel_cache = WheelCache(options.cache_dir, options.format_control)
+
+            with RequirementTracker() as req_tracker, TempDirectory(
+                options.build_dir, delete=build_delete, kind="wheel"
+            ) as directory:
+
+                requirement_set = RequirementSet(
+                    require_hashes=options.require_hashes,
+                )
+
+                try:
+                    self.populate_requirement_set(
+                        requirement_set, args, options, finder, session,
+                        self.name, wheel_cache
+                    )
+
+                    preparer = RequirementPreparer(
+                        build_dir=directory.path,
+                        src_dir=options.src_dir,
+                        download_dir=None,
+                        wheel_download_dir=options.wheel_dir,
+                        progress_bar=options.progress_bar,
+                        build_isolation=options.build_isolation,
+                        req_tracker=req_tracker,
+                    )
+
+                    resolver = Resolver(
+                        preparer=preparer,
+                        finder=finder,
+                        session=session,
+                        wheel_cache=wheel_cache,
+                        use_user_site=False,
+                        upgrade_strategy="to-satisfy-only",
+                        force_reinstall=False,
+                        ignore_dependencies=options.ignore_dependencies,
+                        ignore_requires_python=options.ignore_requires_python,
+                        ignore_installed=True,
+                        isolated=options.isolated_mode,
+                        use_pep517=options.use_pep517
+                    )
+                    resolver.resolve(requirement_set)
+
+                    # build wheels
+                    wb = WheelBuilder(
+                        finder, preparer, wheel_cache,
+                        build_options=options.build_options or [],
+                        global_options=options.global_options or [],
+                        no_clean=options.no_clean,
+                    )
+                    build_failures = wb.build(
+                        requirement_set.requirements.values(), session=session,
+                    )
+                    if len(build_failures) != 0:
+                        raise CommandError(
+                            "Failed to build one or more wheels"
+                        )
+                except PreviousBuildDirError:
+                    options.no_clean = True
+                    raise
+                finally:
+                    if not options.no_clean:
+                        requirement_set.cleanup_files()
+                        wheel_cache.cleanup()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/configuration.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/configuration.py
new file mode 100644
index 0000000..fe6df9b
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/configuration.py
@@ -0,0 +1,387 @@
+"""Configuration management setup
+
+Some terminology:
+- name
+  As written in config files.
+- value
+  Value associated with a name
+- key
+  Name combined with it's section (section.name)
+- variant
+  A single word describing where the configuration key-value pair came from
+"""
+
+import locale
+import logging
+import os
+
+from pip._vendor import six
+from pip._vendor.six.moves import configparser
+
+from pip._internal.exceptions import (
+    ConfigurationError, ConfigurationFileCouldNotBeLoaded,
+)
+from pip._internal.locations import (
+    legacy_config_file, new_config_file, running_under_virtualenv,
+    site_config_files, venv_config_file,
+)
+from pip._internal.utils.misc import ensure_dir, enum
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Any, Dict, Iterable, List, NewType, Optional, Tuple
+    )
+
+    RawConfigParser = configparser.RawConfigParser  # Shorthand
+    Kind = NewType("Kind", str)
+
+logger = logging.getLogger(__name__)
+
+
+# NOTE: Maybe use the optionx attribute to normalize keynames.
+def _normalize_name(name):
+    # type: (str) -> str
+    """Make a name consistent regardless of source (environment or file)
+    """
+    name = name.lower().replace('_', '-')
+    if name.startswith('--'):
+        name = name[2:]  # only prefer long opts
+    return name
+
+
+def _disassemble_key(name):
+    # type: (str) -> List[str]
+    return name.split(".", 1)
+
+
+# The kinds of configurations there are.
+kinds = enum(
+    USER="user",        # User Specific
+    GLOBAL="global",    # System Wide
+    VENV="venv",        # Virtual Environment Specific
+    ENV="env",          # from PIP_CONFIG_FILE
+    ENV_VAR="env-var",  # from Environment Variables
+)
+
+
+class Configuration(object):
+    """Handles management of configuration.
+
+    Provides an interface to accessing and managing configuration files.
+
+    This class converts provides an API that takes "section.key-name" style
+    keys and stores the value associated with it as "key-name" under the
+    section "section".
+
+    This allows for a clean interface wherein the both the section and the
+    key-name are preserved in an easy to manage form in the configuration files
+    and the data stored is also nice.
+    """
+
+    def __init__(self, isolated, load_only=None):
+        # type: (bool, Kind) -> None
+        super(Configuration, self).__init__()
+
+        _valid_load_only = [kinds.USER, kinds.GLOBAL, kinds.VENV, None]
+        if load_only not in _valid_load_only:
+            raise ConfigurationError(
+                "Got invalid value for load_only - should be one of {}".format(
+                    ", ".join(map(repr, _valid_load_only[:-1]))
+                )
+            )
+        self.isolated = isolated  # type: bool
+        self.load_only = load_only  # type: Optional[Kind]
+
+        # The order here determines the override order.
+        self._override_order = [
+            kinds.GLOBAL, kinds.USER, kinds.VENV, kinds.ENV, kinds.ENV_VAR
+        ]
+
+        self._ignore_env_names = ["version", "help"]
+
+        # Because we keep track of where we got the data from
+        self._parsers = {
+            variant: [] for variant in self._override_order
+        }  # type: Dict[Kind, List[Tuple[str, RawConfigParser]]]
+        self._config = {
+            variant: {} for variant in self._override_order
+        }  # type: Dict[Kind, Dict[str, Any]]
+        self._modified_parsers = []  # type: List[Tuple[str, RawConfigParser]]
+
+    def load(self):
+        # type: () -> None
+        """Loads configuration from configuration files and environment
+        """
+        self._load_config_files()
+        if not self.isolated:
+            self._load_environment_vars()
+
+    def get_file_to_edit(self):
+        # type: () -> Optional[str]
+        """Returns the file with highest priority in configuration
+        """
+        assert self.load_only is not None, \
+            "Need to be specified a file to be editing"
+
+        try:
+            return self._get_parser_to_modify()[0]
+        except IndexError:
+            return None
+
+    def items(self):
+        # type: () -> Iterable[Tuple[str, Any]]
+        """Returns key-value pairs like dict.items() representing the loaded
+        configuration
+        """
+        return self._dictionary.items()
+
+    def get_value(self, key):
+        # type: (str) -> Any
+        """Get a value from the configuration.
+        """
+        try:
+            return self._dictionary[key]
+        except KeyError:
+            raise ConfigurationError("No such key - {}".format(key))
+
+    def set_value(self, key, value):
+        # type: (str, Any) -> None
+        """Modify a value in the configuration.
+        """
+        self._ensure_have_load_only()
+
+        fname, parser = self._get_parser_to_modify()
+
+        if parser is not None:
+            section, name = _disassemble_key(key)
+
+            # Modify the parser and the configuration
+            if not parser.has_section(section):
+                parser.add_section(section)
+            parser.set(section, name, value)
+
+        self._config[self.load_only][key] = value
+        self._mark_as_modified(fname, parser)
+
+    def unset_value(self, key):
+        # type: (str) -> None
+        """Unset a value in the configuration.
+        """
+        self._ensure_have_load_only()
+
+        if key not in self._config[self.load_only]:
+            raise ConfigurationError("No such key - {}".format(key))
+
+        fname, parser = self._get_parser_to_modify()
+
+        if parser is not None:
+            section, name = _disassemble_key(key)
+
+            # Remove the key in the parser
+            modified_something = False
+            if parser.has_section(section):
+                # Returns whether the option was removed or not
+                modified_something = parser.remove_option(section, name)
+
+            if modified_something:
+                # name removed from parser, section may now be empty
+                section_iter = iter(parser.items(section))
+                try:
+                    val = six.next(section_iter)
+                except StopIteration:
+                    val = None
+
+                if val is None:
+                    parser.remove_section(section)
+
+                self._mark_as_modified(fname, parser)
+            else:
+                raise ConfigurationError(
+                    "Fatal Internal error [id=1]. Please report as a bug."
+                )
+
+        del self._config[self.load_only][key]
+
+    def save(self):
+        # type: () -> None
+        """Save the currentin-memory state.
+        """
+        self._ensure_have_load_only()
+
+        for fname, parser in self._modified_parsers:
+            logger.info("Writing to %s", fname)
+
+            # Ensure directory exists.
+            ensure_dir(os.path.dirname(fname))
+
+            with open(fname, "w") as f:
+                parser.write(f)  # type: ignore
+
+    #
+    # Private routines
+    #
+
+    def _ensure_have_load_only(self):
+        # type: () -> None
+        if self.load_only is None:
+            raise ConfigurationError("Needed a specific file to be modifying.")
+        logger.debug("Will be working with %s variant only", self.load_only)
+
+    @property
+    def _dictionary(self):
+        # type: () -> Dict[str, Any]
+        """A dictionary representing the loaded configuration.
+        """
+        # NOTE: Dictionaries are not populated if not loaded. So, conditionals
+        #       are not needed here.
+        retval = {}
+
+        for variant in self._override_order:
+            retval.update(self._config[variant])
+
+        return retval
+
+    def _load_config_files(self):
+        # type: () -> None
+        """Loads configuration from configuration files
+        """
+        config_files = dict(self._iter_config_files())
+        if config_files[kinds.ENV][0:1] == [os.devnull]:
+            logger.debug(
+                "Skipping loading configuration files due to "
+                "environment's PIP_CONFIG_FILE being os.devnull"
+            )
+            return
+
+        for variant, files in config_files.items():
+            for fname in files:
+                # If there's specific variant set in `load_only`, load only
+                # that variant, not the others.
+                if self.load_only is not None and variant != self.load_only:
+                    logger.debug(
+                        "Skipping file '%s' (variant: %s)", fname, variant
+                    )
+                    continue
+
+                parser = self._load_file(variant, fname)
+
+                # Keeping track of the parsers used
+                self._parsers[variant].append((fname, parser))
+
+    def _load_file(self, variant, fname):
+        # type: (Kind, str) -> RawConfigParser
+        logger.debug("For variant '%s', will try loading '%s'", variant, fname)
+        parser = self._construct_parser(fname)
+
+        for section in parser.sections():
+            items = parser.items(section)
+            self._config[variant].update(self._normalized_keys(section, items))
+
+        return parser
+
+    def _construct_parser(self, fname):
+        # type: (str) -> RawConfigParser
+        parser = configparser.RawConfigParser()
+        # If there is no such file, don't bother reading it but create the
+        # parser anyway, to hold the data.
+        # Doing this is useful when modifying and saving files, where we don't
+        # need to construct a parser.
+        if os.path.exists(fname):
+            try:
+                parser.read(fname)
+            except UnicodeDecodeError:
+                # See https://github.com/pypa/pip/issues/4963
+                raise ConfigurationFileCouldNotBeLoaded(
+                    reason="contains invalid {} characters".format(
+                        locale.getpreferredencoding(False)
+                    ),
+                    fname=fname,
+                )
+            except configparser.Error as error:
+                # See https://github.com/pypa/pip/issues/4893
+                raise ConfigurationFileCouldNotBeLoaded(error=error)
+        return parser
+
+    def _load_environment_vars(self):
+        # type: () -> None
+        """Loads configuration from environment variables
+        """
+        self._config[kinds.ENV_VAR].update(
+            self._normalized_keys(":env:", self._get_environ_vars())
+        )
+
+    def _normalized_keys(self, section, items):
+        # type: (str, Iterable[Tuple[str, Any]]) -> Dict[str, Any]
+        """Normalizes items to construct a dictionary with normalized keys.
+
+        This routine is where the names become keys and are made the same
+        regardless of source - configuration files or environment.
+        """
+        normalized = {}
+        for name, val in items:
+            key = section + "." + _normalize_name(name)
+            normalized[key] = val
+        return normalized
+
+    def _get_environ_vars(self):
+        # type: () -> Iterable[Tuple[str, str]]
+        """Returns a generator with all environmental vars with prefix PIP_"""
+        for key, val in os.environ.items():
+            should_be_yielded = (
+                key.startswith("PIP_") and
+                key[4:].lower() not in self._ignore_env_names
+            )
+            if should_be_yielded:
+                yield key[4:].lower(), val
+
+    # XXX: This is patched in the tests.
+    def _iter_config_files(self):
+        # type: () -> Iterable[Tuple[Kind, List[str]]]
+        """Yields variant and configuration files associated with it.
+
+        This should be treated like items of a dictionary.
+        """
+        # SMELL: Move the conditions out of this function
+
+        # environment variables have the lowest priority
+        config_file = os.environ.get('PIP_CONFIG_FILE', None)
+        if config_file is not None:
+            yield kinds.ENV, [config_file]
+        else:
+            yield kinds.ENV, []
+
+        # at the base we have any global configuration
+        yield kinds.GLOBAL, list(site_config_files)
+
+        # per-user configuration next
+        should_load_user_config = not self.isolated and not (
+            config_file and os.path.exists(config_file)
+        )
+        if should_load_user_config:
+            # The legacy config file is overridden by the new config file
+            yield kinds.USER, [legacy_config_file, new_config_file]
+
+        # finally virtualenv configuration first trumping others
+        if running_under_virtualenv():
+            yield kinds.VENV, [venv_config_file]
+
+    def _get_parser_to_modify(self):
+        # type: () -> Tuple[str, RawConfigParser]
+        # Determine which parser to modify
+        parsers = self._parsers[self.load_only]
+        if not parsers:
+            # This should not happen if everything works correctly.
+            raise ConfigurationError(
+                "Fatal Internal error [id=2]. Please report as a bug."
+            )
+
+        # Use the highest priority parser.
+        return parsers[-1]
+
+    # XXX: This is patched in the tests.
+    def _mark_as_modified(self, fname, parser):
+        # type: (str, RawConfigParser) -> None
+        file_parser_tuple = (fname, parser)
+        if file_parser_tuple not in self._modified_parsers:
+            self._modified_parsers.append(file_parser_tuple)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/download.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/download.py
new file mode 100644
index 0000000..2bbe176
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/download.py
@@ -0,0 +1,971 @@
+from __future__ import absolute_import
+
+import cgi
+import email.utils
+import getpass
+import json
+import logging
+import mimetypes
+import os
+import platform
+import re
+import shutil
+import sys
+
+from pip._vendor import requests, six, urllib3
+from pip._vendor.cachecontrol import CacheControlAdapter
+from pip._vendor.cachecontrol.caches import FileCache
+from pip._vendor.lockfile import LockError
+from pip._vendor.requests.adapters import BaseAdapter, HTTPAdapter
+from pip._vendor.requests.auth import AuthBase, HTTPBasicAuth
+from pip._vendor.requests.models import CONTENT_CHUNK_SIZE, Response
+from pip._vendor.requests.structures import CaseInsensitiveDict
+from pip._vendor.requests.utils import get_netrc_auth
+# NOTE: XMLRPC Client is not annotated in typeshed as on 2017-07-17, which is
+#       why we ignore the type on this import
+from pip._vendor.six.moves import xmlrpc_client  # type: ignore
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+from pip._vendor.six.moves.urllib import request as urllib_request
+from pip._vendor.urllib3.util import IS_PYOPENSSL
+
+import pip
+from pip._internal.exceptions import HashMismatch, InstallationError
+from pip._internal.locations import write_delete_marker_file
+from pip._internal.models.index import PyPI
+from pip._internal.utils.encoding import auto_decode
+from pip._internal.utils.filesystem import check_path_owner
+from pip._internal.utils.glibc import libc_ver
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    ARCHIVE_EXTENSIONS, ask_path_exists, backup_dir, call_subprocess, consume,
+    display_path, format_size, get_installed_version, rmtree,
+    split_auth_from_netloc, splitext, unpack_file,
+)
+from pip._internal.utils.setuptools_build import SETUPTOOLS_SHIM
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import DownloadProgressProvider
+from pip._internal.vcs import vcs
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Optional, Tuple, Dict, IO, Text, Union
+    )
+    from pip._internal.models.link import Link  # noqa: F401
+    from pip._internal.utils.hashes import Hashes  # noqa: F401
+    from pip._internal.vcs import AuthInfo  # noqa: F401
+
+try:
+    import ssl  # noqa
+except ImportError:
+    ssl = None
+
+HAS_TLS = (ssl is not None) or IS_PYOPENSSL
+
+__all__ = ['get_file_content',
+           'is_url', 'url_to_path', 'path_to_url',
+           'is_archive_file', 'unpack_vcs_link',
+           'unpack_file_url', 'is_vcs_url', 'is_file_url',
+           'unpack_http_url', 'unpack_url']
+
+
+logger = logging.getLogger(__name__)
+
+
+def user_agent():
+    """
+    Return a string representing the user agent.
+    """
+    data = {
+        "installer": {"name": "pip", "version": pip.__version__},
+        "python": platform.python_version(),
+        "implementation": {
+            "name": platform.python_implementation(),
+        },
+    }
+
+    if data["implementation"]["name"] == 'CPython':
+        data["implementation"]["version"] = platform.python_version()
+    elif data["implementation"]["name"] == 'PyPy':
+        if sys.pypy_version_info.releaselevel == 'final':
+            pypy_version_info = sys.pypy_version_info[:3]
+        else:
+            pypy_version_info = sys.pypy_version_info
+        data["implementation"]["version"] = ".".join(
+            [str(x) for x in pypy_version_info]
+        )
+    elif data["implementation"]["name"] == 'Jython':
+        # Complete Guess
+        data["implementation"]["version"] = platform.python_version()
+    elif data["implementation"]["name"] == 'IronPython':
+        # Complete Guess
+        data["implementation"]["version"] = platform.python_version()
+
+    if sys.platform.startswith("linux"):
+        from pip._vendor import distro
+        distro_infos = dict(filter(
+            lambda x: x[1],
+            zip(["name", "version", "id"], distro.linux_distribution()),
+        ))
+        libc = dict(filter(
+            lambda x: x[1],
+            zip(["lib", "version"], libc_ver()),
+        ))
+        if libc:
+            distro_infos["libc"] = libc
+        if distro_infos:
+            data["distro"] = distro_infos
+
+    if sys.platform.startswith("darwin") and platform.mac_ver()[0]:
+        data["distro"] = {"name": "macOS", "version": platform.mac_ver()[0]}
+
+    if platform.system():
+        data.setdefault("system", {})["name"] = platform.system()
+
+    if platform.release():
+        data.setdefault("system", {})["release"] = platform.release()
+
+    if platform.machine():
+        data["cpu"] = platform.machine()
+
+    if HAS_TLS:
+        data["openssl_version"] = ssl.OPENSSL_VERSION
+
+    setuptools_version = get_installed_version("setuptools")
+    if setuptools_version is not None:
+        data["setuptools_version"] = setuptools_version
+
+    return "{data[installer][name]}/{data[installer][version]} {json}".format(
+        data=data,
+        json=json.dumps(data, separators=(",", ":"), sort_keys=True),
+    )
+
+
+class MultiDomainBasicAuth(AuthBase):
+
+    def __init__(self, prompting=True):
+        # type: (bool) -> None
+        self.prompting = prompting
+        self.passwords = {}  # type: Dict[str, AuthInfo]
+
+    def __call__(self, req):
+        parsed = urllib_parse.urlparse(req.url)
+
+        # Split the credentials from the netloc.
+        netloc, url_user_password = split_auth_from_netloc(parsed.netloc)
+
+        # Set the url of the request to the url without any credentials
+        req.url = urllib_parse.urlunparse(parsed[:1] + (netloc,) + parsed[2:])
+
+        # Use any stored credentials that we have for this netloc
+        username, password = self.passwords.get(netloc, (None, None))
+
+        # Use the credentials embedded in the url if we have none stored
+        if username is None:
+            username, password = url_user_password
+
+        # Get creds from netrc if we still don't have them
+        if username is None and password is None:
+            netrc_auth = get_netrc_auth(req.url)
+            username, password = netrc_auth if netrc_auth else (None, None)
+
+        if username or password:
+            # Store the username and password
+            self.passwords[netloc] = (username, password)
+
+            # Send the basic auth with this request
+            req = HTTPBasicAuth(username or "", password or "")(req)
+
+        # Attach a hook to handle 401 responses
+        req.register_hook("response", self.handle_401)
+
+        return req
+
+    def handle_401(self, resp, **kwargs):
+        # We only care about 401 responses, anything else we want to just
+        #   pass through the actual response
+        if resp.status_code != 401:
+            return resp
+
+        # We are not able to prompt the user so simply return the response
+        if not self.prompting:
+            return resp
+
+        parsed = urllib_parse.urlparse(resp.url)
+
+        # Prompt the user for a new username and password
+        username = six.moves.input("User for %s: " % parsed.netloc)
+        password = getpass.getpass("Password: ")
+
+        # Store the new username and password to use for future requests
+        if username or password:
+            self.passwords[parsed.netloc] = (username, password)
+
+        # Consume content and release the original connection to allow our new
+        #   request to reuse the same one.
+        resp.content
+        resp.raw.release_conn()
+
+        # Add our new username and password to the request
+        req = HTTPBasicAuth(username or "", password or "")(resp.request)
+        req.register_hook("response", self.warn_on_401)
+
+        # Send our new request
+        new_resp = resp.connection.send(req, **kwargs)
+        new_resp.history.append(resp)
+
+        return new_resp
+
+    def warn_on_401(self, resp, **kwargs):
+        # warn user that they provided incorrect credentials
+        if resp.status_code == 401:
+            logger.warning('401 Error, Credentials not correct for %s',
+                           resp.request.url)
+
+
+class LocalFSAdapter(BaseAdapter):
+
+    def send(self, request, stream=None, timeout=None, verify=None, cert=None,
+             proxies=None):
+        pathname = url_to_path(request.url)
+
+        resp = Response()
+        resp.status_code = 200
+        resp.url = request.url
+
+        try:
+            stats = os.stat(pathname)
+        except OSError as exc:
+            resp.status_code = 404
+            resp.raw = exc
+        else:
+            modified = email.utils.formatdate(stats.st_mtime, usegmt=True)
+            content_type = mimetypes.guess_type(pathname)[0] or "text/plain"
+            resp.headers = CaseInsensitiveDict({
+                "Content-Type": content_type,
+                "Content-Length": stats.st_size,
+                "Last-Modified": modified,
+            })
+
+            resp.raw = open(pathname, "rb")
+            resp.close = resp.raw.close
+
+        return resp
+
+    def close(self):
+        pass
+
+
+class SafeFileCache(FileCache):
+    """
+    A file based cache which is safe to use even when the target directory may
+    not be accessible or writable.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super(SafeFileCache, self).__init__(*args, **kwargs)
+
+        # Check to ensure that the directory containing our cache directory
+        # is owned by the user current executing pip. If it does not exist
+        # we will check the parent directory until we find one that does exist.
+        # If it is not owned by the user executing pip then we will disable
+        # the cache and log a warning.
+        if not check_path_owner(self.directory):
+            logger.warning(
+                "The directory '%s' or its parent directory is not owned by "
+                "the current user and the cache has been disabled. Please "
+                "check the permissions and owner of that directory. If "
+                "executing pip with sudo, you may want sudo's -H flag.",
+                self.directory,
+            )
+
+            # Set our directory to None to disable the Cache
+            self.directory = None
+
+    def get(self, *args, **kwargs):
+        # If we don't have a directory, then the cache should be a no-op.
+        if self.directory is None:
+            return
+
+        try:
+            return super(SafeFileCache, self).get(*args, **kwargs)
+        except (LockError, OSError, IOError):
+            # We intentionally silence this error, if we can't access the cache
+            # then we can just skip caching and process the request as if
+            # caching wasn't enabled.
+            pass
+
+    def set(self, *args, **kwargs):
+        # If we don't have a directory, then the cache should be a no-op.
+        if self.directory is None:
+            return
+
+        try:
+            return super(SafeFileCache, self).set(*args, **kwargs)
+        except (LockError, OSError, IOError):
+            # We intentionally silence this error, if we can't access the cache
+            # then we can just skip caching and process the request as if
+            # caching wasn't enabled.
+            pass
+
+    def delete(self, *args, **kwargs):
+        # If we don't have a directory, then the cache should be a no-op.
+        if self.directory is None:
+            return
+
+        try:
+            return super(SafeFileCache, self).delete(*args, **kwargs)
+        except (LockError, OSError, IOError):
+            # We intentionally silence this error, if we can't access the cache
+            # then we can just skip caching and process the request as if
+            # caching wasn't enabled.
+            pass
+
+
+class InsecureHTTPAdapter(HTTPAdapter):
+
+    def cert_verify(self, conn, url, verify, cert):
+        conn.cert_reqs = 'CERT_NONE'
+        conn.ca_certs = None
+
+
+class PipSession(requests.Session):
+
+    timeout = None  # type: Optional[int]
+
+    def __init__(self, *args, **kwargs):
+        retries = kwargs.pop("retries", 0)
+        cache = kwargs.pop("cache", None)
+        insecure_hosts = kwargs.pop("insecure_hosts", [])
+
+        super(PipSession, self).__init__(*args, **kwargs)
+
+        # Attach our User Agent to the request
+        self.headers["User-Agent"] = user_agent()
+
+        # Attach our Authentication handler to the session
+        self.auth = MultiDomainBasicAuth()
+
+        # Create our urllib3.Retry instance which will allow us to customize
+        # how we handle retries.
+        retries = urllib3.Retry(
+            # Set the total number of retries that a particular request can
+            # have.
+            total=retries,
+
+            # A 503 error from PyPI typically means that the Fastly -> Origin
+            # connection got interrupted in some way. A 503 error in general
+            # is typically considered a transient error so we'll go ahead and
+            # retry it.
+            # A 500 may indicate transient error in Amazon S3
+            # A 520 or 527 - may indicate transient error in CloudFlare
+            status_forcelist=[500, 503, 520, 527],
+
+            # Add a small amount of back off between failed requests in
+            # order to prevent hammering the service.
+            backoff_factor=0.25,
+        )
+
+        # We want to _only_ cache responses on securely fetched origins. We do
+        # this because we can't validate the response of an insecurely fetched
+        # origin, and we don't want someone to be able to poison the cache and
+        # require manual eviction from the cache to fix it.
+        if cache:
+            secure_adapter = CacheControlAdapter(
+                cache=SafeFileCache(cache, use_dir_lock=True),
+                max_retries=retries,
+            )
+        else:
+            secure_adapter = HTTPAdapter(max_retries=retries)
+
+        # Our Insecure HTTPAdapter disables HTTPS validation. It does not
+        # support caching (see above) so we'll use it for all http:// URLs as
+        # well as any https:// host that we've marked as ignoring TLS errors
+        # for.
+        insecure_adapter = InsecureHTTPAdapter(max_retries=retries)
+
+        self.mount("https://", secure_adapter)
+        self.mount("http://", insecure_adapter)
+
+        # Enable file:// urls
+        self.mount("file://", LocalFSAdapter())
+
+        # We want to use a non-validating adapter for any requests which are
+        # deemed insecure.
+        for host in insecure_hosts:
+            self.mount("https://{}/".format(host), insecure_adapter)
+
+    def request(self, method, url, *args, **kwargs):
+        # Allow setting a default timeout on a session
+        kwargs.setdefault("timeout", self.timeout)
+
+        # Dispatch the actual request
+        return super(PipSession, self).request(method, url, *args, **kwargs)
+
+
+def get_file_content(url, comes_from=None, session=None):
+    # type: (str, Optional[str], Optional[PipSession]) -> Tuple[str, Text]
+    """Gets the content of a file; it may be a filename, file: URL, or
+    http: URL.  Returns (location, content).  Content is unicode.
+
+    :param url:         File path or url.
+    :param comes_from:  Origin description of requirements.
+    :param session:     Instance of pip.download.PipSession.
+    """
+    if session is None:
+        raise TypeError(
+            "get_file_content() missing 1 required keyword argument: 'session'"
+        )
+
+    match = _scheme_re.search(url)
+    if match:
+        scheme = match.group(1).lower()
+        if (scheme == 'file' and comes_from and
+                comes_from.startswith('http')):
+            raise InstallationError(
+                'Requirements file %s references URL %s, which is local'
+                % (comes_from, url))
+        if scheme == 'file':
+            path = url.split(':', 1)[1]
+            path = path.replace('\\', '/')
+            match = _url_slash_drive_re.match(path)
+            if match:
+                path = match.group(1) + ':' + path.split('|', 1)[1]
+            path = urllib_parse.unquote(path)
+            if path.startswith('/'):
+                path = '/' + path.lstrip('/')
+            url = path
+        else:
+            # FIXME: catch some errors
+            resp = session.get(url)
+            resp.raise_for_status()
+            return resp.url, resp.text
+    try:
+        with open(url, 'rb') as f:
+            content = auto_decode(f.read())
+    except IOError as exc:
+        raise InstallationError(
+            'Could not open requirements file: %s' % str(exc)
+        )
+    return url, content
+
+
+_scheme_re = re.compile(r'^(http|https|file):', re.I)
+_url_slash_drive_re = re.compile(r'/*([a-z])\|', re.I)
+
+
+def is_url(name):
+    # type: (Union[str, Text]) -> bool
+    """Returns true if the name looks like a URL"""
+    if ':' not in name:
+        return False
+    scheme = name.split(':', 1)[0].lower()
+    return scheme in ['http', 'https', 'file', 'ftp'] + vcs.all_schemes
+
+
+def url_to_path(url):
+    # type: (str) -> str
+    """
+    Convert a file: URL to a path.
+    """
+    assert url.startswith('file:'), (
+        "You can only turn file: urls into filenames (not %r)" % url)
+
+    _, netloc, path, _, _ = urllib_parse.urlsplit(url)
+
+    # if we have a UNC path, prepend UNC share notation
+    if netloc:
+        netloc = '\\\\' + netloc
+
+    path = urllib_request.url2pathname(netloc + path)
+    return path
+
+
+def path_to_url(path):
+    # type: (Union[str, Text]) -> str
+    """
+    Convert a path to a file: URL.  The path will be made absolute and have
+    quoted path parts.
+    """
+    path = os.path.normpath(os.path.abspath(path))
+    url = urllib_parse.urljoin('file:', urllib_request.pathname2url(path))
+    return url
+
+
+def is_archive_file(name):
+    # type: (str) -> bool
+    """Return True if `name` is a considered as an archive file."""
+    ext = splitext(name)[1].lower()
+    if ext in ARCHIVE_EXTENSIONS:
+        return True
+    return False
+
+
+def unpack_vcs_link(link, location):
+    vcs_backend = _get_used_vcs_backend(link)
+    vcs_backend.unpack(location)
+
+
+def _get_used_vcs_backend(link):
+    for backend in vcs.backends:
+        if link.scheme in backend.schemes:
+            vcs_backend = backend(link.url)
+            return vcs_backend
+
+
+def is_vcs_url(link):
+    # type: (Link) -> bool
+    return bool(_get_used_vcs_backend(link))
+
+
+def is_file_url(link):
+    # type: (Link) -> bool
+    return link.url.lower().startswith('file:')
+
+
+def is_dir_url(link):
+    # type: (Link) -> bool
+    """Return whether a file:// Link points to a directory.
+
+    ``link`` must not have any other scheme but file://. Call is_file_url()
+    first.
+
+    """
+    link_path = url_to_path(link.url_without_fragment)
+    return os.path.isdir(link_path)
+
+
+def _progress_indicator(iterable, *args, **kwargs):
+    return iterable
+
+
+def _download_url(
+    resp,  # type: Response
+    link,  # type: Link
+    content_file,  # type: IO
+    hashes,  # type: Hashes
+    progress_bar  # type: str
+):
+    # type: (...) -> None
+    try:
+        total_length = int(resp.headers['content-length'])
+    except (ValueError, KeyError, TypeError):
+        total_length = 0
+
+    cached_resp = getattr(resp, "from_cache", False)
+    if logger.getEffectiveLevel() > logging.INFO:
+        show_progress = False
+    elif cached_resp:
+        show_progress = False
+    elif total_length > (40 * 1000):
+        show_progress = True
+    elif not total_length:
+        show_progress = True
+    else:
+        show_progress = False
+
+    show_url = link.show_url
+
+    def resp_read(chunk_size):
+        try:
+            # Special case for urllib3.
+            for chunk in resp.raw.stream(
+                    chunk_size,
+                    # We use decode_content=False here because we don't
+                    # want urllib3 to mess with the raw bytes we get
+                    # from the server. If we decompress inside of
+                    # urllib3 then we cannot verify the checksum
+                    # because the checksum will be of the compressed
+                    # file. This breakage will only occur if the
+                    # server adds a Content-Encoding header, which
+                    # depends on how the server was configured:
+                    # - Some servers will notice that the file isn't a
+                    #   compressible file and will leave the file alone
+                    #   and with an empty Content-Encoding
+                    # - Some servers will notice that the file is
+                    #   already compressed and will leave the file
+                    #   alone and will add a Content-Encoding: gzip
+                    #   header
+                    # - Some servers won't notice anything at all and
+                    #   will take a file that's already been compressed
+                    #   and compress it again and set the
+                    #   Content-Encoding: gzip header
+                    #
+                    # By setting this not to decode automatically we
+                    # hope to eliminate problems with the second case.
+                    decode_content=False):
+                yield chunk
+        except AttributeError:
+            # Standard file-like object.
+            while True:
+                chunk = resp.raw.read(chunk_size)
+                if not chunk:
+                    break
+                yield chunk
+
+    def written_chunks(chunks):
+        for chunk in chunks:
+            content_file.write(chunk)
+            yield chunk
+
+    progress_indicator = _progress_indicator
+
+    if link.netloc == PyPI.netloc:
+        url = show_url
+    else:
+        url = link.url_without_fragment
+
+    if show_progress:  # We don't show progress on cached responses
+        progress_indicator = DownloadProgressProvider(progress_bar,
+                                                      max=total_length)
+        if total_length:
+            logger.info("Downloading %s (%s)", url, format_size(total_length))
+        else:
+            logger.info("Downloading %s", url)
+    elif cached_resp:
+        logger.info("Using cached %s", url)
+    else:
+        logger.info("Downloading %s", url)
+
+    logger.debug('Downloading from URL %s', link)
+
+    downloaded_chunks = written_chunks(
+        progress_indicator(
+            resp_read(CONTENT_CHUNK_SIZE),
+            CONTENT_CHUNK_SIZE
+        )
+    )
+    if hashes:
+        hashes.check_against_chunks(downloaded_chunks)
+    else:
+        consume(downloaded_chunks)
+
+
+def _copy_file(filename, location, link):
+    copy = True
+    download_location = os.path.join(location, link.filename)
+    if os.path.exists(download_location):
+        response = ask_path_exists(
+            'The file %s exists. (i)gnore, (w)ipe, (b)ackup, (a)abort' %
+            display_path(download_location), ('i', 'w', 'b', 'a'))
+        if response == 'i':
+            copy = False
+        elif response == 'w':
+            logger.warning('Deleting %s', display_path(download_location))
+            os.remove(download_location)
+        elif response == 'b':
+            dest_file = backup_dir(download_location)
+            logger.warning(
+                'Backing up %s to %s',
+                display_path(download_location),
+                display_path(dest_file),
+            )
+            shutil.move(download_location, dest_file)
+        elif response == 'a':
+            sys.exit(-1)
+    if copy:
+        shutil.copy(filename, download_location)
+        logger.info('Saved %s', display_path(download_location))
+
+
+def unpack_http_url(
+    link,  # type: Link
+    location,  # type: str
+    download_dir=None,  # type: Optional[str]
+    session=None,  # type: Optional[PipSession]
+    hashes=None,  # type: Optional[Hashes]
+    progress_bar="on"  # type: str
+):
+    # type: (...) -> None
+    if session is None:
+        raise TypeError(
+            "unpack_http_url() missing 1 required keyword argument: 'session'"
+        )
+
+    with TempDirectory(kind="unpack") as temp_dir:
+        # If a download dir is specified, is the file already downloaded there?
+        already_downloaded_path = None
+        if download_dir:
+            already_downloaded_path = _check_download_dir(link,
+                                                          download_dir,
+                                                          hashes)
+
+        if already_downloaded_path:
+            from_path = already_downloaded_path
+            content_type = mimetypes.guess_type(from_path)[0]
+        else:
+            # let's download to a tmp dir
+            from_path, content_type = _download_http_url(link,
+                                                         session,
+                                                         temp_dir.path,
+                                                         hashes,
+                                                         progress_bar)
+
+        # unpack the archive to the build dir location. even when only
+        # downloading archives, they have to be unpacked to parse dependencies
+        unpack_file(from_path, location, content_type, link)
+
+        # a download dir is specified; let's copy the archive there
+        if download_dir and not already_downloaded_path:
+            _copy_file(from_path, download_dir, link)
+
+        if not already_downloaded_path:
+            os.unlink(from_path)
+
+
+def unpack_file_url(
+    link,  # type: Link
+    location,  # type: str
+    download_dir=None,  # type: Optional[str]
+    hashes=None  # type: Optional[Hashes]
+):
+    # type: (...) -> None
+    """Unpack link into location.
+
+    If download_dir is provided and link points to a file, make a copy
+    of the link file inside download_dir.
+    """
+    link_path = url_to_path(link.url_without_fragment)
+
+    # If it's a url to a local directory
+    if is_dir_url(link):
+        if os.path.isdir(location):
+            rmtree(location)
+        shutil.copytree(link_path, location, symlinks=True)
+        if download_dir:
+            logger.info('Link is a directory, ignoring download_dir')
+        return
+
+    # If --require-hashes is off, `hashes` is either empty, the
+    # link's embedded hash, or MissingHashes; it is required to
+    # match. If --require-hashes is on, we are satisfied by any
+    # hash in `hashes` matching: a URL-based or an option-based
+    # one; no internet-sourced hash will be in `hashes`.
+    if hashes:
+        hashes.check_against_path(link_path)
+
+    # If a download dir is specified, is the file already there and valid?
+    already_downloaded_path = None
+    if download_dir:
+        already_downloaded_path = _check_download_dir(link,
+                                                      download_dir,
+                                                      hashes)
+
+    if already_downloaded_path:
+        from_path = already_downloaded_path
+    else:
+        from_path = link_path
+
+    content_type = mimetypes.guess_type(from_path)[0]
+
+    # unpack the archive to the build dir location. even when only downloading
+    # archives, they have to be unpacked to parse dependencies
+    unpack_file(from_path, location, content_type, link)
+
+    # a download dir is specified and not already downloaded
+    if download_dir and not already_downloaded_path:
+        _copy_file(from_path, download_dir, link)
+
+
+def _copy_dist_from_dir(link_path, location):
+    """Copy distribution files in `link_path` to `location`.
+
+    Invoked when user requests to install a local directory. E.g.:
+
+        pip install .
+        pip install ~/dev/git-repos/python-prompt-toolkit
+
+    """
+
+    # Note: This is currently VERY SLOW if you have a lot of data in the
+    # directory, because it copies everything with `shutil.copytree`.
+    # What it should really do is build an sdist and install that.
+    # See https://github.com/pypa/pip/issues/2195
+
+    if os.path.isdir(location):
+        rmtree(location)
+
+    # build an sdist
+    setup_py = 'setup.py'
+    sdist_args = [sys.executable]
+    sdist_args.append('-c')
+    sdist_args.append(SETUPTOOLS_SHIM % setup_py)
+    sdist_args.append('sdist')
+    sdist_args += ['--dist-dir', location]
+    logger.info('Running setup.py sdist for %s', link_path)
+
+    with indent_log():
+        call_subprocess(sdist_args, cwd=link_path, show_stdout=False)
+
+    # unpack sdist into `location`
+    sdist = os.path.join(location, os.listdir(location)[0])
+    logger.info('Unpacking sdist %s into %s', sdist, location)
+    unpack_file(sdist, location, content_type=None, link=None)
+
+
+class PipXmlrpcTransport(xmlrpc_client.Transport):
+    """Provide a `xmlrpclib.Transport` implementation via a `PipSession`
+    object.
+    """
+
+    def __init__(self, index_url, session, use_datetime=False):
+        xmlrpc_client.Transport.__init__(self, use_datetime)
+        index_parts = urllib_parse.urlparse(index_url)
+        self._scheme = index_parts.scheme
+        self._session = session
+
+    def request(self, host, handler, request_body, verbose=False):
+        parts = (self._scheme, host, handler, None, None, None)
+        url = urllib_parse.urlunparse(parts)
+        try:
+            headers = {'Content-Type': 'text/xml'}
+            response = self._session.post(url, data=request_body,
+                                          headers=headers, stream=True)
+            response.raise_for_status()
+            self.verbose = verbose
+            return self.parse_response(response.raw)
+        except requests.HTTPError as exc:
+            logger.critical(
+                "HTTP error %s while getting %s",
+                exc.response.status_code, url,
+            )
+            raise
+
+
+def unpack_url(
+    link,  # type: Optional[Link]
+    location,  # type: Optional[str]
+    download_dir=None,  # type: Optional[str]
+    only_download=False,  # type: bool
+    session=None,  # type: Optional[PipSession]
+    hashes=None,  # type: Optional[Hashes]
+    progress_bar="on"  # type: str
+):
+    # type: (...) -> None
+    """Unpack link.
+       If link is a VCS link:
+         if only_download, export into download_dir and ignore location
+          else unpack into location
+       for other types of link:
+         - unpack into location
+         - if download_dir, copy the file into download_dir
+         - if only_download, mark location for deletion
+
+    :param hashes: A Hashes object, one of whose embedded hashes must match,
+        or HashMismatch will be raised. If the Hashes is empty, no matches are
+        required, and unhashable types of requirements (like VCS ones, which
+        would ordinarily raise HashUnsupported) are allowed.
+    """
+    # non-editable vcs urls
+    if is_vcs_url(link):
+        unpack_vcs_link(link, location)
+
+    # file urls
+    elif is_file_url(link):
+        unpack_file_url(link, location, download_dir, hashes=hashes)
+
+    # http urls
+    else:
+        if session is None:
+            session = PipSession()
+
+        unpack_http_url(
+            link,
+            location,
+            download_dir,
+            session,
+            hashes=hashes,
+            progress_bar=progress_bar
+        )
+    if only_download:
+        write_delete_marker_file(location)
+
+
+def _download_http_url(
+    link,  # type: Link
+    session,  # type: PipSession
+    temp_dir,  # type: str
+    hashes,  # type: Hashes
+    progress_bar  # type: str
+):
+    # type: (...) -> Tuple[str, str]
+    """Download link url into temp_dir using provided session"""
+    target_url = link.url.split('#', 1)[0]
+    try:
+        resp = session.get(
+            target_url,
+            # We use Accept-Encoding: identity here because requests
+            # defaults to accepting compressed responses. This breaks in
+            # a variety of ways depending on how the server is configured.
+            # - Some servers will notice that the file isn't a compressible
+            #   file and will leave the file alone and with an empty
+            #   Content-Encoding
+            # - Some servers will notice that the file is already
+            #   compressed and will leave the file alone and will add a
+            #   Content-Encoding: gzip header
+            # - Some servers won't notice anything at all and will take
+            #   a file that's already been compressed and compress it again
+            #   and set the Content-Encoding: gzip header
+            # By setting this to request only the identity encoding We're
+            # hoping to eliminate the third case. Hopefully there does not
+            # exist a server which when given a file will notice it is
+            # already compressed and that you're not asking for a
+            # compressed file and will then decompress it before sending
+            # because if that's the case I don't think it'll ever be
+            # possible to make this work.
+            headers={"Accept-Encoding": "identity"},
+            stream=True,
+        )
+        resp.raise_for_status()
+    except requests.HTTPError as exc:
+        logger.critical(
+            "HTTP error %s while getting %s", exc.response.status_code, link,
+        )
+        raise
+
+    content_type = resp.headers.get('content-type', '')
+    filename = link.filename  # fallback
+    # Have a look at the Content-Disposition header for a better guess
+    content_disposition = resp.headers.get('content-disposition')
+    if content_disposition:
+        type, params = cgi.parse_header(content_disposition)
+        # We use ``or`` here because we don't want to use an "empty" value
+        # from the filename param.
+        filename = params.get('filename') or filename
+    ext = splitext(filename)[1]
+    if not ext:
+        ext = mimetypes.guess_extension(content_type)
+        if ext:
+            filename += ext
+    if not ext and link.url != resp.url:
+        ext = os.path.splitext(resp.url)[1]
+        if ext:
+            filename += ext
+    file_path = os.path.join(temp_dir, filename)
+    with open(file_path, 'wb') as content_file:
+        _download_url(resp, link, content_file, hashes, progress_bar)
+    return file_path, content_type
+
+
+def _check_download_dir(link, download_dir, hashes):
+    # type: (Link, str, Hashes) -> Optional[str]
+    """ Check download_dir for previously downloaded file with correct hash
+        If a correct file is found return its path else None
+    """
+    download_path = os.path.join(download_dir, link.filename)
+    if os.path.exists(download_path):
+        # If already downloaded, does its hash match?
+        logger.info('File was already downloaded %s', download_path)
+        if hashes:
+            try:
+                hashes.check_against_path(download_path)
+            except HashMismatch:
+                logger.warning(
+                    'Previously-downloaded file %s has bad hash. '
+                    'Re-downloading.',
+                    download_path
+                )
+                os.unlink(download_path)
+                return None
+        return download_path
+    return None
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/exceptions.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/exceptions.py
new file mode 100644
index 0000000..38ceeea
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/exceptions.py
@@ -0,0 +1,274 @@
+"""Exceptions used throughout package"""
+from __future__ import absolute_import
+
+from itertools import chain, groupby, repeat
+
+from pip._vendor.six import iteritems
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+
+
+class PipError(Exception):
+    """Base pip exception"""
+
+
+class ConfigurationError(PipError):
+    """General exception in configuration"""
+
+
+class InstallationError(PipError):
+    """General exception during installation"""
+
+
+class UninstallationError(PipError):
+    """General exception during uninstallation"""
+
+
+class DistributionNotFound(InstallationError):
+    """Raised when a distribution cannot be found to satisfy a requirement"""
+
+
+class RequirementsFileParseError(InstallationError):
+    """Raised when a general error occurs parsing a requirements file line."""
+
+
+class BestVersionAlreadyInstalled(PipError):
+    """Raised when the most up-to-date version of a package is already
+    installed."""
+
+
+class BadCommand(PipError):
+    """Raised when virtualenv or a command is not found"""
+
+
+class CommandError(PipError):
+    """Raised when there is an error in command-line arguments"""
+
+
+class PreviousBuildDirError(PipError):
+    """Raised when there's a previous conflicting build directory"""
+
+
+class InvalidWheelFilename(InstallationError):
+    """Invalid wheel filename."""
+
+
+class UnsupportedWheel(InstallationError):
+    """Unsupported wheel."""
+
+
+class HashErrors(InstallationError):
+    """Multiple HashError instances rolled into one for reporting"""
+
+    def __init__(self):
+        self.errors = []
+
+    def append(self, error):
+        self.errors.append(error)
+
+    def __str__(self):
+        lines = []
+        self.errors.sort(key=lambda e: e.order)
+        for cls, errors_of_cls in groupby(self.errors, lambda e: e.__class__):
+            lines.append(cls.head)
+            lines.extend(e.body() for e in errors_of_cls)
+        if lines:
+            return '\n'.join(lines)
+
+    def __nonzero__(self):
+        return bool(self.errors)
+
+    def __bool__(self):
+        return self.__nonzero__()
+
+
+class HashError(InstallationError):
+    """
+    A failure to verify a package against known-good hashes
+
+    :cvar order: An int sorting hash exception classes by difficulty of
+        recovery (lower being harder), so the user doesn't bother fretting
+        about unpinned packages when he has deeper issues, like VCS
+        dependencies, to deal with. Also keeps error reports in a
+        deterministic order.
+    :cvar head: A section heading for display above potentially many
+        exceptions of this kind
+    :ivar req: The InstallRequirement that triggered this error. This is
+        pasted on after the exception is instantiated, because it's not
+        typically available earlier.
+
+    """
+    req = None  # type: Optional[InstallRequirement]
+    head = ''
+
+    def body(self):
+        """Return a summary of me for display under the heading.
+
+        This default implementation simply prints a description of the
+        triggering requirement.
+
+        :param req: The InstallRequirement that provoked this error, with
+            populate_link() having already been called
+
+        """
+        return '    %s' % self._requirement_name()
+
+    def __str__(self):
+        return '%s\n%s' % (self.head, self.body())
+
+    def _requirement_name(self):
+        """Return a description of the requirement that triggered me.
+
+        This default implementation returns long description of the req, with
+        line numbers
+
+        """
+        return str(self.req) if self.req else 'unknown package'
+
+
+class VcsHashUnsupported(HashError):
+    """A hash was provided for a version-control-system-based requirement, but
+    we don't have a method for hashing those."""
+
+    order = 0
+    head = ("Can't verify hashes for these requirements because we don't "
+            "have a way to hash version control repositories:")
+
+
+class DirectoryUrlHashUnsupported(HashError):
+    """A hash was provided for a version-control-system-based requirement, but
+    we don't have a method for hashing those."""
+
+    order = 1
+    head = ("Can't verify hashes for these file:// requirements because they "
+            "point to directories:")
+
+
+class HashMissing(HashError):
+    """A hash was needed for a requirement but is absent."""
+
+    order = 2
+    head = ('Hashes are required in --require-hashes mode, but they are '
+            'missing from some requirements. Here is a list of those '
+            'requirements along with the hashes their downloaded archives '
+            'actually had. Add lines like these to your requirements files to '
+            'prevent tampering. (If you did not enable --require-hashes '
+            'manually, note that it turns on automatically when any package '
+            'has a hash.)')
+
+    def __init__(self, gotten_hash):
+        """
+        :param gotten_hash: The hash of the (possibly malicious) archive we
+            just downloaded
+        """
+        self.gotten_hash = gotten_hash
+
+    def body(self):
+        # Dodge circular import.
+        from pip._internal.utils.hashes import FAVORITE_HASH
+
+        package = None
+        if self.req:
+            # In the case of URL-based requirements, display the original URL
+            # seen in the requirements file rather than the package name,
+            # so the output can be directly copied into the requirements file.
+            package = (self.req.original_link if self.req.original_link
+                       # In case someone feeds something downright stupid
+                       # to InstallRequirement's constructor.
+                       else getattr(self.req, 'req', None))
+        return '    %s --hash=%s:%s' % (package or 'unknown package',
+                                        FAVORITE_HASH,
+                                        self.gotten_hash)
+
+
+class HashUnpinned(HashError):
+    """A requirement had a hash specified but was not pinned to a specific
+    version."""
+
+    order = 3
+    head = ('In --require-hashes mode, all requirements must have their '
+            'versions pinned with ==. These do not:')
+
+
+class HashMismatch(HashError):
+    """
+    Distribution file hash values don't match.
+
+    :ivar package_name: The name of the package that triggered the hash
+        mismatch. Feel free to write to this after the exception is raise to
+        improve its error message.
+
+    """
+    order = 4
+    head = ('THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS '
+            'FILE. If you have updated the package versions, please update '
+            'the hashes. Otherwise, examine the package contents carefully; '
+            'someone may have tampered with them.')
+
+    def __init__(self, allowed, gots):
+        """
+        :param allowed: A dict of algorithm names pointing to lists of allowed
+            hex digests
+        :param gots: A dict of algorithm names pointing to hashes we
+            actually got from the files under suspicion
+        """
+        self.allowed = allowed
+        self.gots = gots
+
+    def body(self):
+        return '    %s:\n%s' % (self._requirement_name(),
+                                self._hash_comparison())
+
+    def _hash_comparison(self):
+        """
+        Return a comparison of actual and expected hash values.
+
+        Example::
+
+               Expected sha256 abcdeabcdeabcdeabcdeabcdeabcdeabcdeabcdeabcde
+                            or 123451234512345123451234512345123451234512345
+                    Got        bcdefbcdefbcdefbcdefbcdefbcdefbcdefbcdefbcdef
+
+        """
+        def hash_then_or(hash_name):
+            # For now, all the decent hashes have 6-char names, so we can get
+            # away with hard-coding space literals.
+            return chain([hash_name], repeat('    or'))
+
+        lines = []
+        for hash_name, expecteds in iteritems(self.allowed):
+            prefix = hash_then_or(hash_name)
+            lines.extend(('        Expected %s %s' % (next(prefix), e))
+                         for e in expecteds)
+            lines.append('             Got        %s\n' %
+                         self.gots[hash_name].hexdigest())
+            prefix = '    or'
+        return '\n'.join(lines)
+
+
+class UnsupportedPythonVersion(InstallationError):
+    """Unsupported python version according to Requires-Python package
+    metadata."""
+
+
+class ConfigurationFileCouldNotBeLoaded(ConfigurationError):
+    """When there are errors while loading a configuration file
+    """
+
+    def __init__(self, reason="could not be loaded", fname=None, error=None):
+        super(ConfigurationFileCouldNotBeLoaded, self).__init__(error)
+        self.reason = reason
+        self.fname = fname
+        self.error = error
+
+    def __str__(self):
+        if self.fname is not None:
+            message_part = " in {}.".format(self.fname)
+        else:
+            assert self.error is not None
+            message_part = ".\n{}\n".format(self.error.message)
+        return "Configuration file {}{}".format(self.reason, message_part)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/index.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/index.py
new file mode 100644
index 0000000..9eda3a3
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/index.py
@@ -0,0 +1,990 @@
+"""Routines related to PyPI, indexes"""
+from __future__ import absolute_import
+
+import cgi
+import itertools
+import logging
+import mimetypes
+import os
+import posixpath
+import re
+import sys
+from collections import namedtuple
+
+from pip._vendor import html5lib, requests, six
+from pip._vendor.distlib.compat import unescape
+from pip._vendor.packaging import specifiers
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.packaging.version import parse as parse_version
+from pip._vendor.requests.exceptions import RetryError, SSLError
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+from pip._vendor.six.moves.urllib import request as urllib_request
+
+from pip._internal.download import HAS_TLS, is_url, path_to_url, url_to_path
+from pip._internal.exceptions import (
+    BestVersionAlreadyInstalled, DistributionNotFound, InvalidWheelFilename,
+    UnsupportedWheel,
+)
+from pip._internal.models.candidate import InstallationCandidate
+from pip._internal.models.format_control import FormatControl
+from pip._internal.models.index import PyPI
+from pip._internal.models.link import Link
+from pip._internal.pep425tags import get_supported
+from pip._internal.utils.compat import ipaddress
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    ARCHIVE_EXTENSIONS, SUPPORTED_EXTENSIONS, WHEEL_EXTENSION, normalize_path,
+    redact_password_from_url,
+)
+from pip._internal.utils.packaging import check_requires_python
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.wheel import Wheel
+
+if MYPY_CHECK_RUNNING:
+    from logging import Logger  # noqa: F401
+    from typing import (  # noqa: F401
+        Tuple, Optional, Any, List, Union, Callable, Set, Sequence,
+        Iterable, MutableMapping
+    )
+    from pip._vendor.packaging.version import _BaseVersion  # noqa: F401
+    from pip._vendor.requests import Response  # noqa: F401
+    from pip._internal.req import InstallRequirement  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+
+    SecureOrigin = Tuple[str, str, Optional[str]]
+    BuildTag = Tuple[Any, ...]  # either emply tuple or Tuple[int, str]
+    CandidateSortingKey = Tuple[int, _BaseVersion, BuildTag, Optional[int]]
+
+__all__ = ['FormatControl', 'PackageFinder']
+
+
+SECURE_ORIGINS = [
+    # protocol, hostname, port
+    # Taken from Chrome's list of secure origins (See: http://bit.ly/1qrySKC)
+    ("https", "*", "*"),
+    ("*", "localhost", "*"),
+    ("*", "127.0.0.0/8", "*"),
+    ("*", "::1/128", "*"),
+    ("file", "*", None),
+    # ssh is always secure.
+    ("ssh", "*", "*"),
+]  # type: List[SecureOrigin]
+
+
+logger = logging.getLogger(__name__)
+
+
+def _match_vcs_scheme(url):
+    # type: (str) -> Optional[str]
+    """Look for VCS schemes in the URL.
+
+    Returns the matched VCS scheme, or None if there's no match.
+    """
+    from pip._internal.vcs import VcsSupport
+    for scheme in VcsSupport.schemes:
+        if url.lower().startswith(scheme) and url[len(scheme)] in '+:':
+            return scheme
+    return None
+
+
+def _is_url_like_archive(url):
+    # type: (str) -> bool
+    """Return whether the URL looks like an archive.
+    """
+    filename = Link(url).filename
+    for bad_ext in ARCHIVE_EXTENSIONS:
+        if filename.endswith(bad_ext):
+            return True
+    return False
+
+
+class _NotHTML(Exception):
+    def __init__(self, content_type, request_desc):
+        # type: (str, str) -> None
+        super(_NotHTML, self).__init__(content_type, request_desc)
+        self.content_type = content_type
+        self.request_desc = request_desc
+
+
+def _ensure_html_header(response):
+    # type: (Response) -> None
+    """Check the Content-Type header to ensure the response contains HTML.
+
+    Raises `_NotHTML` if the content type is not text/html.
+    """
+    content_type = response.headers.get("Content-Type", "")
+    if not content_type.lower().startswith("text/html"):
+        raise _NotHTML(content_type, response.request.method)
+
+
+class _NotHTTP(Exception):
+    pass
+
+
+def _ensure_html_response(url, session):
+    # type: (str, PipSession) -> None
+    """Send a HEAD request to the URL, and ensure the response contains HTML.
+
+    Raises `_NotHTTP` if the URL is not available for a HEAD request, or
+    `_NotHTML` if the content type is not text/html.
+    """
+    scheme, netloc, path, query, fragment = urllib_parse.urlsplit(url)
+    if scheme not in {'http', 'https'}:
+        raise _NotHTTP()
+
+    resp = session.head(url, allow_redirects=True)
+    resp.raise_for_status()
+
+    _ensure_html_header(resp)
+
+
+def _get_html_response(url, session):
+    # type: (str, PipSession) -> Response
+    """Access an HTML page with GET, and return the response.
+
+    This consists of three parts:
+
+    1. If the URL looks suspiciously like an archive, send a HEAD first to
+       check the Content-Type is HTML, to avoid downloading a large file.
+       Raise `_NotHTTP` if the content type cannot be determined, or
+       `_NotHTML` if it is not HTML.
+    2. Actually perform the request. Raise HTTP exceptions on network failures.
+    3. Check the Content-Type header to make sure we got HTML, and raise
+       `_NotHTML` otherwise.
+    """
+    if _is_url_like_archive(url):
+        _ensure_html_response(url, session=session)
+
+    logger.debug('Getting page %s', url)
+
+    resp = session.get(
+        url,
+        headers={
+            "Accept": "text/html",
+            # We don't want to blindly returned cached data for
+            # /simple/, because authors generally expecting that
+            # twine upload && pip install will function, but if
+            # they've done a pip install in the last ~10 minutes
+            # it won't. Thus by setting this to zero we will not
+            # blindly use any cached data, however the benefit of
+            # using max-age=0 instead of no-cache, is that we will
+            # still support conditional requests, so we will still
+            # minimize traffic sent in cases where the page hasn't
+            # changed at all, we will just always incur the round
+            # trip for the conditional GET now instead of only
+            # once per 10 minutes.
+            # For more information, please see pypa/pip#5670.
+            "Cache-Control": "max-age=0",
+        },
+    )
+    resp.raise_for_status()
+
+    # The check for archives above only works if the url ends with
+    # something that looks like an archive. However that is not a
+    # requirement of an url. Unless we issue a HEAD request on every
+    # url we cannot know ahead of time for sure if something is HTML
+    # or not. However we can check after we've downloaded it.
+    _ensure_html_header(resp)
+
+    return resp
+
+
+def _handle_get_page_fail(
+    link,  # type: Link
+    reason,  # type: Union[str, Exception]
+    meth=None  # type: Optional[Callable[..., None]]
+):
+    # type: (...) -> None
+    if meth is None:
+        meth = logger.debug
+    meth("Could not fetch URL %s: %s - skipping", link, reason)
+
+
+def _get_html_page(link, session=None):
+    # type: (Link, Optional[PipSession]) -> Optional[HTMLPage]
+    if session is None:
+        raise TypeError(
+            "_get_html_page() missing 1 required keyword argument: 'session'"
+        )
+
+    url = link.url.split('#', 1)[0]
+
+    # Check for VCS schemes that do not support lookup as web pages.
+    vcs_scheme = _match_vcs_scheme(url)
+    if vcs_scheme:
+        logger.debug('Cannot look at %s URL %s', vcs_scheme, link)
+        return None
+
+    # Tack index.html onto file:// URLs that point to directories
+    scheme, _, path, _, _, _ = urllib_parse.urlparse(url)
+    if (scheme == 'file' and os.path.isdir(urllib_request.url2pathname(path))):
+        # add trailing slash if not present so urljoin doesn't trim
+        # final segment
+        if not url.endswith('/'):
+            url += '/'
+        url = urllib_parse.urljoin(url, 'index.html')
+        logger.debug(' file: URL is directory, getting %s', url)
+
+    try:
+        resp = _get_html_response(url, session=session)
+    except _NotHTTP as exc:
+        logger.debug(
+            'Skipping page %s because it looks like an archive, and cannot '
+            'be checked by HEAD.', link,
+        )
+    except _NotHTML as exc:
+        logger.debug(
+            'Skipping page %s because the %s request got Content-Type: %s',
+            link, exc.request_desc, exc.content_type,
+        )
+    except requests.HTTPError as exc:
+        _handle_get_page_fail(link, exc)
+    except RetryError as exc:
+        _handle_get_page_fail(link, exc)
+    except SSLError as exc:
+        reason = "There was a problem confirming the ssl certificate: "
+        reason += str(exc)
+        _handle_get_page_fail(link, reason, meth=logger.info)
+    except requests.ConnectionError as exc:
+        _handle_get_page_fail(link, "connection error: %s" % exc)
+    except requests.Timeout:
+        _handle_get_page_fail(link, "timed out")
+    else:
+        return HTMLPage(resp.content, resp.url, resp.headers)
+    return None
+
+
+class PackageFinder(object):
+    """This finds packages.
+
+    This is meant to match easy_install's technique for looking for
+    packages, by reading pages and looking for appropriate links.
+    """
+
+    def __init__(
+        self,
+        find_links,  # type: List[str]
+        index_urls,  # type: List[str]
+        allow_all_prereleases=False,  # type: bool
+        trusted_hosts=None,  # type: Optional[Iterable[str]]
+        session=None,  # type: Optional[PipSession]
+        format_control=None,  # type: Optional[FormatControl]
+        platform=None,  # type: Optional[str]
+        versions=None,  # type: Optional[List[str]]
+        abi=None,  # type: Optional[str]
+        implementation=None,  # type: Optional[str]
+        prefer_binary=False  # type: bool
+    ):
+        # type: (...) -> None
+        """Create a PackageFinder.
+
+        :param format_control: A FormatControl object or None. Used to control
+            the selection of source packages / binary packages when consulting
+            the index and links.
+        :param platform: A string or None. If None, searches for packages
+            that are supported by the current system. Otherwise, will find
+            packages that can be built on the platform passed in. These
+            packages will only be downloaded for distribution: they will
+            not be built locally.
+        :param versions: A list of strings or None. This is passed directly
+            to pep425tags.py in the get_supported() method.
+        :param abi: A string or None. This is passed directly
+            to pep425tags.py in the get_supported() method.
+        :param implementation: A string or None. This is passed directly
+            to pep425tags.py in the get_supported() method.
+        """
+        if session is None:
+            raise TypeError(
+                "PackageFinder() missing 1 required keyword argument: "
+                "'session'"
+            )
+
+        # Build find_links. If an argument starts with ~, it may be
+        # a local file relative to a home directory. So try normalizing
+        # it and if it exists, use the normalized version.
+        # This is deliberately conservative - it might be fine just to
+        # blindly normalize anything starting with a ~...
+        self.find_links = []  # type: List[str]
+        for link in find_links:
+            if link.startswith('~'):
+                new_link = normalize_path(link)
+                if os.path.exists(new_link):
+                    link = new_link
+            self.find_links.append(link)
+
+        self.index_urls = index_urls
+
+        # These are boring links that have already been logged somehow:
+        self.logged_links = set()  # type: Set[Link]
+
+        self.format_control = format_control or FormatControl(set(), set())
+
+        # Domains that we won't emit warnings for when not using HTTPS
+        self.secure_origins = [
+            ("*", host, "*")
+            for host in (trusted_hosts if trusted_hosts else [])
+        ]  # type: List[SecureOrigin]
+
+        # Do we want to allow _all_ pre-releases?
+        self.allow_all_prereleases = allow_all_prereleases
+
+        # The Session we'll use to make requests
+        self.session = session
+
+        # The valid tags to check potential found wheel candidates against
+        self.valid_tags = get_supported(
+            versions=versions,
+            platform=platform,
+            abi=abi,
+            impl=implementation,
+        )
+
+        # Do we prefer old, but valid, binary dist over new source dist
+        self.prefer_binary = prefer_binary
+
+        # If we don't have TLS enabled, then WARN if anyplace we're looking
+        # relies on TLS.
+        if not HAS_TLS:
+            for link in itertools.chain(self.index_urls, self.find_links):
+                parsed = urllib_parse.urlparse(link)
+                if parsed.scheme == "https":
+                    logger.warning(
+                        "pip is configured with locations that require "
+                        "TLS/SSL, however the ssl module in Python is not "
+                        "available."
+                    )
+                    break
+
+    def get_formatted_locations(self):
+        # type: () -> str
+        lines = []
+        if self.index_urls and self.index_urls != [PyPI.simple_url]:
+            lines.append(
+                "Looking in indexes: {}".format(", ".join(
+                    redact_password_from_url(url) for url in self.index_urls))
+            )
+        if self.find_links:
+            lines.append(
+                "Looking in links: {}".format(", ".join(self.find_links))
+            )
+        return "\n".join(lines)
+
+    @staticmethod
+    def _sort_locations(locations, expand_dir=False):
+        # type: (Sequence[str], bool) -> Tuple[List[str], List[str]]
+        """
+        Sort locations into "files" (archives) and "urls", and return
+        a pair of lists (files,urls)
+        """
+        files = []
+        urls = []
+
+        # puts the url for the given file path into the appropriate list
+        def sort_path(path):
+            url = path_to_url(path)
+            if mimetypes.guess_type(url, strict=False)[0] == 'text/html':
+                urls.append(url)
+            else:
+                files.append(url)
+
+        for url in locations:
+
+            is_local_path = os.path.exists(url)
+            is_file_url = url.startswith('file:')
+
+            if is_local_path or is_file_url:
+                if is_local_path:
+                    path = url
+                else:
+                    path = url_to_path(url)
+                if os.path.isdir(path):
+                    if expand_dir:
+                        path = os.path.realpath(path)
+                        for item in os.listdir(path):
+                            sort_path(os.path.join(path, item))
+                    elif is_file_url:
+                        urls.append(url)
+                    else:
+                        logger.warning(
+                            "Path '{0}' is ignored: "
+                            "it is a directory.".format(path),
+                        )
+                elif os.path.isfile(path):
+                    sort_path(path)
+                else:
+                    logger.warning(
+                        "Url '%s' is ignored: it is neither a file "
+                        "nor a directory.", url,
+                    )
+            elif is_url(url):
+                # Only add url with clear scheme
+                urls.append(url)
+            else:
+                logger.warning(
+                    "Url '%s' is ignored. It is either a non-existing "
+                    "path or lacks a specific scheme.", url,
+                )
+
+        return files, urls
+
+    def _candidate_sort_key(self, candidate):
+        # type: (InstallationCandidate) -> CandidateSortingKey
+        """
+        Function used to generate link sort key for link tuples.
+        The greater the return value, the more preferred it is.
+        If not finding wheels, then sorted by version only.
+        If finding wheels, then the sort order is by version, then:
+          1. existing installs
+          2. wheels ordered via Wheel.support_index_min(self.valid_tags)
+          3. source archives
+        If prefer_binary was set, then all wheels are sorted above sources.
+        Note: it was considered to embed this logic into the Link
+              comparison operators, but then different sdist links
+              with the same version, would have to be considered equal
+        """
+        support_num = len(self.valid_tags)
+        build_tag = tuple()  # type: BuildTag
+        binary_preference = 0
+        if candidate.location.is_wheel:
+            # can raise InvalidWheelFilename
+            wheel = Wheel(candidate.location.filename)
+            if not wheel.supported(self.valid_tags):
+                raise UnsupportedWheel(
+                    "%s is not a supported wheel for this platform. It "
+                    "can't be sorted." % wheel.filename
+                )
+            if self.prefer_binary:
+                binary_preference = 1
+            pri = -(wheel.support_index_min(self.valid_tags))
+            if wheel.build_tag is not None:
+                match = re.match(r'^(\d+)(.*)$', wheel.build_tag)
+                build_tag_groups = match.groups()
+                build_tag = (int(build_tag_groups[0]), build_tag_groups[1])
+        else:  # sdist
+            pri = -(support_num)
+        return (binary_preference, candidate.version, build_tag, pri)
+
+    def _validate_secure_origin(self, logger, location):
+        # type: (Logger, Link) -> bool
+        # Determine if this url used a secure transport mechanism
+        parsed = urllib_parse.urlparse(str(location))
+        origin = (parsed.scheme, parsed.hostname, parsed.port)
+
+        # The protocol to use to see if the protocol matches.
+        # Don't count the repository type as part of the protocol: in
+        # cases such as "git+ssh", only use "ssh". (I.e., Only verify against
+        # the last scheme.)
+        protocol = origin[0].rsplit('+', 1)[-1]
+
+        # Determine if our origin is a secure origin by looking through our
+        # hardcoded list of secure origins, as well as any additional ones
+        # configured on this PackageFinder instance.
+        for secure_origin in (SECURE_ORIGINS + self.secure_origins):
+            if protocol != secure_origin[0] and secure_origin[0] != "*":
+                continue
+
+            try:
+                # We need to do this decode dance to ensure that we have a
+                # unicode object, even on Python 2.x.
+                addr = ipaddress.ip_address(
+                    origin[1]
+                    if (
+                        isinstance(origin[1], six.text_type) or
+                        origin[1] is None
+                    )
+                    else origin[1].decode("utf8")
+                )
+                network = ipaddress.ip_network(
+                    secure_origin[1]
+                    if isinstance(secure_origin[1], six.text_type)
+                    # setting secure_origin[1] to proper Union[bytes, str]
+                    # creates problems in other places
+                    else secure_origin[1].decode("utf8")  # type: ignore
+                )
+            except ValueError:
+                # We don't have both a valid address or a valid network, so
+                # we'll check this origin against hostnames.
+                if (origin[1] and
+                        origin[1].lower() != secure_origin[1].lower() and
+                        secure_origin[1] != "*"):
+                    continue
+            else:
+                # We have a valid address and network, so see if the address
+                # is contained within the network.
+                if addr not in network:
+                    continue
+
+            # Check to see if the port patches
+            if (origin[2] != secure_origin[2] and
+                    secure_origin[2] != "*" and
+                    secure_origin[2] is not None):
+                continue
+
+            # If we've gotten here, then this origin matches the current
+            # secure origin and we should return True
+            return True
+
+        # If we've gotten to this point, then the origin isn't secure and we
+        # will not accept it as a valid location to search. We will however
+        # log a warning that we are ignoring it.
+        logger.warning(
+            "The repository located at %s is not a trusted or secure host and "
+            "is being ignored. If this repository is available via HTTPS we "
+            "recommend you use HTTPS instead, otherwise you may silence "
+            "this warning and allow it anyway with '--trusted-host %s'.",
+            parsed.hostname,
+            parsed.hostname,
+        )
+
+        return False
+
+    def _get_index_urls_locations(self, project_name):
+        # type: (str) -> List[str]
+        """Returns the locations found via self.index_urls
+
+        Checks the url_name on the main (first in the list) index and
+        use this url_name to produce all locations
+        """
+
+        def mkurl_pypi_url(url):
+            loc = posixpath.join(
+                url,
+                urllib_parse.quote(canonicalize_name(project_name)))
+            # For maximum compatibility with easy_install, ensure the path
+            # ends in a trailing slash.  Although this isn't in the spec
+            # (and PyPI can handle it without the slash) some other index
+            # implementations might break if they relied on easy_install's
+            # behavior.
+            if not loc.endswith('/'):
+                loc = loc + '/'
+            return loc
+
+        return [mkurl_pypi_url(url) for url in self.index_urls]
+
+    def find_all_candidates(self, project_name):
+        # type: (str) -> List[Optional[InstallationCandidate]]
+        """Find all available InstallationCandidate for project_name
+
+        This checks index_urls and find_links.
+        All versions found are returned as an InstallationCandidate list.
+
+        See _link_package_versions for details on which files are accepted
+        """
+        index_locations = self._get_index_urls_locations(project_name)
+        index_file_loc, index_url_loc = self._sort_locations(index_locations)
+        fl_file_loc, fl_url_loc = self._sort_locations(
+            self.find_links, expand_dir=True,
+        )
+
+        file_locations = (Link(url) for url in itertools.chain(
+            index_file_loc, fl_file_loc,
+        ))
+
+        # We trust every url that the user has given us whether it was given
+        #   via --index-url or --find-links.
+        # We want to filter out any thing which does not have a secure origin.
+        url_locations = [
+            link for link in itertools.chain(
+                (Link(url) for url in index_url_loc),
+                (Link(url) for url in fl_url_loc),
+            )
+            if self._validate_secure_origin(logger, link)
+        ]
+
+        logger.debug('%d location(s) to search for versions of %s:',
+                     len(url_locations), project_name)
+
+        for location in url_locations:
+            logger.debug('* %s', location)
+
+        canonical_name = canonicalize_name(project_name)
+        formats = self.format_control.get_allowed_formats(canonical_name)
+        search = Search(project_name, canonical_name, formats)
+        find_links_versions = self._package_versions(
+            # We trust every directly linked archive in find_links
+            (Link(url, '-f') for url in self.find_links),
+            search
+        )
+
+        page_versions = []
+        for page in self._get_pages(url_locations, project_name):
+            logger.debug('Analyzing links from page %s', page.url)
+            with indent_log():
+                page_versions.extend(
+                    self._package_versions(page.iter_links(), search)
+                )
+
+        file_versions = self._package_versions(file_locations, search)
+        if file_versions:
+            file_versions.sort(reverse=True)
+            logger.debug(
+                'Local files found: %s',
+                ', '.join([
+                    url_to_path(candidate.location.url)
+                    for candidate in file_versions
+                ])
+            )
+
+        # This is an intentional priority ordering
+        return file_versions + find_links_versions + page_versions
+
+    def find_requirement(self, req, upgrade):
+        # type: (InstallRequirement, bool) -> Optional[Link]
+        """Try to find a Link matching req
+
+        Expects req, an InstallRequirement and upgrade, a boolean
+        Returns a Link if found,
+        Raises DistributionNotFound or BestVersionAlreadyInstalled otherwise
+        """
+        all_candidates = self.find_all_candidates(req.name)
+
+        # Filter out anything which doesn't match our specifier
+        compatible_versions = set(
+            req.specifier.filter(
+                # We turn the version object into a str here because otherwise
+                # when we're debundled but setuptools isn't, Python will see
+                # packaging.version.Version and
+                # pkg_resources._vendor.packaging.version.Version as different
+                # types. This way we'll use a str as a common data interchange
+                # format. If we stop using the pkg_resources provided specifier
+                # and start using our own, we can drop the cast to str().
+                [str(c.version) for c in all_candidates],
+                prereleases=(
+                    self.allow_all_prereleases
+                    if self.allow_all_prereleases else None
+                ),
+            )
+        )
+        applicable_candidates = [
+            # Again, converting to str to deal with debundling.
+            c for c in all_candidates if str(c.version) in compatible_versions
+        ]
+
+        if applicable_candidates:
+            best_candidate = max(applicable_candidates,
+                                 key=self._candidate_sort_key)
+        else:
+            best_candidate = None
+
+        if req.satisfied_by is not None:
+            installed_version = parse_version(req.satisfied_by.version)
+        else:
+            installed_version = None
+
+        if installed_version is None and best_candidate is None:
+            logger.critical(
+                'Could not find a version that satisfies the requirement %s '
+                '(from versions: %s)',
+                req,
+                ', '.join(
+                    sorted(
+                        {str(c.version) for c in all_candidates},
+                        key=parse_version,
+                    )
+                )
+            )
+
+            raise DistributionNotFound(
+                'No matching distribution found for %s' % req
+            )
+
+        best_installed = False
+        if installed_version and (
+                best_candidate is None or
+                best_candidate.version <= installed_version):
+            best_installed = True
+
+        if not upgrade and installed_version is not None:
+            if best_installed:
+                logger.debug(
+                    'Existing installed version (%s) is most up-to-date and '
+                    'satisfies requirement',
+                    installed_version,
+                )
+            else:
+                logger.debug(
+                    'Existing installed version (%s) satisfies requirement '
+                    '(most up-to-date version is %s)',
+                    installed_version,
+                    best_candidate.version,
+                )
+            return None
+
+        if best_installed:
+            # We have an existing version, and its the best version
+            logger.debug(
+                'Installed version (%s) is most up-to-date (past versions: '
+                '%s)',
+                installed_version,
+                ', '.join(sorted(compatible_versions, key=parse_version)) or
+                "none",
+            )
+            raise BestVersionAlreadyInstalled
+
+        logger.debug(
+            'Using version %s (newest of versions: %s)',
+            best_candidate.version,
+            ', '.join(sorted(compatible_versions, key=parse_version))
+        )
+        return best_candidate.location
+
+    def _get_pages(self, locations, project_name):
+        # type: (Iterable[Link], str) -> Iterable[HTMLPage]
+        """
+        Yields (page, page_url) from the given locations, skipping
+        locations that have errors.
+        """
+        seen = set()  # type: Set[Link]
+        for location in locations:
+            if location in seen:
+                continue
+            seen.add(location)
+
+            page = _get_html_page(location, session=self.session)
+            if page is None:
+                continue
+
+            yield page
+
+    _py_version_re = re.compile(r'-py([123]\.?[0-9]?)$')
+
+    def _sort_links(self, links):
+        # type: (Iterable[Link]) -> List[Link]
+        """
+        Returns elements of links in order, non-egg links first, egg links
+        second, while eliminating duplicates
+        """
+        eggs, no_eggs = [], []
+        seen = set()  # type: Set[Link]
+        for link in links:
+            if link not in seen:
+                seen.add(link)
+                if link.egg_fragment:
+                    eggs.append(link)
+                else:
+                    no_eggs.append(link)
+        return no_eggs + eggs
+
+    def _package_versions(
+        self,
+        links,  # type: Iterable[Link]
+        search  # type: Search
+    ):
+        # type: (...) -> List[Optional[InstallationCandidate]]
+        result = []
+        for link in self._sort_links(links):
+            v = self._link_package_versions(link, search)
+            if v is not None:
+                result.append(v)
+        return result
+
+    def _log_skipped_link(self, link, reason):
+        # type: (Link, str) -> None
+        if link not in self.logged_links:
+            logger.debug('Skipping link %s; %s', link, reason)
+            self.logged_links.add(link)
+
+    def _link_package_versions(self, link, search):
+        # type: (Link, Search) -> Optional[InstallationCandidate]
+        """Return an InstallationCandidate or None"""
+        version = None
+        if link.egg_fragment:
+            egg_info = link.egg_fragment
+            ext = link.ext
+        else:
+            egg_info, ext = link.splitext()
+            if not ext:
+                self._log_skipped_link(link, 'not a file')
+                return None
+            if ext not in SUPPORTED_EXTENSIONS:
+                self._log_skipped_link(
+                    link, 'unsupported archive format: %s' % ext,
+                )
+                return None
+            if "binary" not in search.formats and ext == WHEEL_EXTENSION:
+                self._log_skipped_link(
+                    link, 'No binaries permitted for %s' % search.supplied,
+                )
+                return None
+            if "macosx10" in link.path and ext == '.zip':
+                self._log_skipped_link(link, 'macosx10 one')
+                return None
+            if ext == WHEEL_EXTENSION:
+                try:
+                    wheel = Wheel(link.filename)
+                except InvalidWheelFilename:
+                    self._log_skipped_link(link, 'invalid wheel filename')
+                    return None
+                if canonicalize_name(wheel.name) != search.canonical:
+                    self._log_skipped_link(
+                        link, 'wrong project name (not %s)' % search.supplied)
+                    return None
+
+                if not wheel.supported(self.valid_tags):
+                    self._log_skipped_link(
+                        link, 'it is not compatible with this Python')
+                    return None
+
+                version = wheel.version
+
+        # This should be up by the search.ok_binary check, but see issue 2700.
+        if "source" not in search.formats and ext != WHEEL_EXTENSION:
+            self._log_skipped_link(
+                link, 'No sources permitted for %s' % search.supplied,
+            )
+            return None
+
+        if not version:
+            version = _egg_info_matches(egg_info, search.canonical)
+        if not version:
+            self._log_skipped_link(
+                link, 'Missing project version for %s' % search.supplied)
+            return None
+
+        match = self._py_version_re.search(version)
+        if match:
+            version = version[:match.start()]
+            py_version = match.group(1)
+            if py_version != sys.version[:3]:
+                self._log_skipped_link(
+                    link, 'Python version is incorrect')
+                return None
+        try:
+            support_this_python = check_requires_python(link.requires_python)
+        except specifiers.InvalidSpecifier:
+            logger.debug("Package %s has an invalid Requires-Python entry: %s",
+                         link.filename, link.requires_python)
+            support_this_python = True
+
+        if not support_this_python:
+            logger.debug("The package %s is incompatible with the python "
+                         "version in use. Acceptable python versions are: %s",
+                         link, link.requires_python)
+            return None
+        logger.debug('Found link %s, version: %s', link, version)
+
+        return InstallationCandidate(search.supplied, version, link)
+
+
+def _find_name_version_sep(egg_info, canonical_name):
+    # type: (str, str) -> int
+    """Find the separator's index based on the package's canonical name.
+
+    `egg_info` must be an egg info string for the given package, and
+    `canonical_name` must be the package's canonical name.
+
+    This function is needed since the canonicalized name does not necessarily
+    have the same length as the egg info's name part. An example::
+
+    >>> egg_info = 'foo__bar-1.0'
+    >>> canonical_name = 'foo-bar'
+    >>> _find_name_version_sep(egg_info, canonical_name)
+    8
+    """
+    # Project name and version must be separated by one single dash. Find all
+    # occurrences of dashes; if the string in front of it matches the canonical
+    # name, this is the one separating the name and version parts.
+    for i, c in enumerate(egg_info):
+        if c != "-":
+            continue
+        if canonicalize_name(egg_info[:i]) == canonical_name:
+            return i
+    raise ValueError("{} does not match {}".format(egg_info, canonical_name))
+
+
+def _egg_info_matches(egg_info, canonical_name):
+    # type: (str, str) -> Optional[str]
+    """Pull the version part out of a string.
+
+    :param egg_info: The string to parse. E.g. foo-2.1
+    :param canonical_name: The canonicalized name of the package this
+        belongs to.
+    """
+    try:
+        version_start = _find_name_version_sep(egg_info, canonical_name) + 1
+    except ValueError:
+        return None
+    version = egg_info[version_start:]
+    if not version:
+        return None
+    return version
+
+
+def _determine_base_url(document, page_url):
+    """Determine the HTML document's base URL.
+
+    This looks for a ``<base>`` tag in the HTML document. If present, its href
+    attribute denotes the base URL of anchor tags in the document. If there is
+    no such tag (or if it does not have a valid href attribute), the HTML
+    file's URL is used as the base URL.
+
+    :param document: An HTML document representation. The current
+        implementation expects the result of ``html5lib.parse()``.
+    :param page_url: The URL of the HTML document.
+    """
+    for base in document.findall(".//base"):
+        href = base.get("href")
+        if href is not None:
+            return href
+    return page_url
+
+
+def _get_encoding_from_headers(headers):
+    """Determine if we have any encoding information in our headers.
+    """
+    if headers and "Content-Type" in headers:
+        content_type, params = cgi.parse_header(headers["Content-Type"])
+        if "charset" in params:
+            return params['charset']
+    return None
+
+
+_CLEAN_LINK_RE = re.compile(r'[^a-z0-9$&+,/:;=?@.#%_\\|-]', re.I)
+
+
+def _clean_link(url):
+    # type: (str) -> str
+    """Makes sure a link is fully encoded.  That is, if a ' ' shows up in
+    the link, it will be rewritten to %20 (while not over-quoting
+    % or other characters)."""
+    return _CLEAN_LINK_RE.sub(lambda match: '%%%2x' % ord(match.group(0)), url)
+
+
+class HTMLPage(object):
+    """Represents one page, along with its URL"""
+
+    def __init__(self, content, url, headers=None):
+        # type: (bytes, str, MutableMapping[str, str]) -> None
+        self.content = content
+        self.url = url
+        self.headers = headers
+
+    def __str__(self):
+        return redact_password_from_url(self.url)
+
+    def iter_links(self):
+        # type: () -> Iterable[Link]
+        """Yields all links in the page"""
+        document = html5lib.parse(
+            self.content,
+            transport_encoding=_get_encoding_from_headers(self.headers),
+            namespaceHTMLElements=False,
+        )
+        base_url = _determine_base_url(document, self.url)
+        for anchor in document.findall(".//a"):
+            if anchor.get("href"):
+                href = anchor.get("href")
+                url = _clean_link(urllib_parse.urljoin(base_url, href))
+                pyrequire = anchor.get('data-requires-python')
+                pyrequire = unescape(pyrequire) if pyrequire else None
+                yield Link(url, self.url, requires_python=pyrequire)
+
+
+Search = namedtuple('Search', 'supplied canonical formats')
+"""Capture key aspects of a search.
+
+:attribute supplied: The user supplied package.
+:attribute canonical: The canonical package name.
+:attribute formats: The formats allowed for this package. Should be a set
+    with 'binary' or 'source' or both in it.
+"""
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/locations.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/locations.py
new file mode 100644
index 0000000..c6e2a3e
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/locations.py
@@ -0,0 +1,211 @@
+"""Locations where we look for configs, install stuff, etc"""
+from __future__ import absolute_import
+
+import os
+import os.path
+import platform
+import site
+import sys
+import sysconfig
+from distutils import sysconfig as distutils_sysconfig
+from distutils.command.install import SCHEME_KEYS  # type: ignore
+
+from pip._internal.utils import appdirs
+from pip._internal.utils.compat import WINDOWS, expanduser
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Union, Dict, List, Optional  # noqa: F401
+
+
+# Application Directories
+USER_CACHE_DIR = appdirs.user_cache_dir("pip")
+
+
+DELETE_MARKER_MESSAGE = '''\
+This file is placed here by pip to indicate the source was put
+here by pip.
+
+Once this package is successfully installed this source code will be
+deleted (unless you remove this file).
+'''
+PIP_DELETE_MARKER_FILENAME = 'pip-delete-this-directory.txt'
+
+
+def write_delete_marker_file(directory):
+    # type: (str) -> None
+    """
+    Write the pip delete marker file into this directory.
+    """
+    filepath = os.path.join(directory, PIP_DELETE_MARKER_FILENAME)
+    with open(filepath, 'w') as marker_fp:
+        marker_fp.write(DELETE_MARKER_MESSAGE)
+
+
+def running_under_virtualenv():
+    # type: () -> bool
+    """
+    Return True if we're running inside a virtualenv, False otherwise.
+
+    """
+    if hasattr(sys, 'real_prefix'):
+        return True
+    elif sys.prefix != getattr(sys, "base_prefix", sys.prefix):
+        return True
+
+    return False
+
+
+def virtualenv_no_global():
+    # type: () -> bool
+    """
+    Return True if in a venv and no system site packages.
+    """
+    # this mirrors the logic in virtualenv.py for locating the
+    # no-global-site-packages.txt file
+    site_mod_dir = os.path.dirname(os.path.abspath(site.__file__))
+    no_global_file = os.path.join(site_mod_dir, 'no-global-site-packages.txt')
+    if running_under_virtualenv() and os.path.isfile(no_global_file):
+        return True
+    else:
+        return False
+
+
+if running_under_virtualenv():
+    src_prefix = os.path.join(sys.prefix, 'src')
+else:
+    # FIXME: keep src in cwd for now (it is not a temporary folder)
+    try:
+        src_prefix = os.path.join(os.getcwd(), 'src')
+    except OSError:
+        # In case the current working directory has been renamed or deleted
+        sys.exit(
+            "The folder you are executing pip from can no longer be found."
+        )
+
+# under macOS + virtualenv sys.prefix is not properly resolved
+# it is something like /path/to/python/bin/..
+# Note: using realpath due to tmp dirs on OSX being symlinks
+src_prefix = os.path.abspath(src_prefix)
+
+# FIXME doesn't account for venv linked to global site-packages
+
+site_packages = sysconfig.get_path("purelib")  # type: Optional[str]
+
+# This is because of a bug in PyPy's sysconfig module, see
+# https://bitbucket.org/pypy/pypy/issues/2506/sysconfig-returns-incorrect-paths
+# for more information.
+if platform.python_implementation().lower() == "pypy":
+    site_packages = distutils_sysconfig.get_python_lib()
+try:
+    # Use getusersitepackages if this is present, as it ensures that the
+    # value is initialised properly.
+    user_site = site.getusersitepackages()
+except AttributeError:
+    user_site = site.USER_SITE
+user_dir = expanduser('~')
+if WINDOWS:
+    bin_py = os.path.join(sys.prefix, 'Scripts')
+    bin_user = os.path.join(user_site, 'Scripts')
+    # buildout uses 'bin' on Windows too?
+    if not os.path.exists(bin_py):
+        bin_py = os.path.join(sys.prefix, 'bin')
+        bin_user = os.path.join(user_site, 'bin')
+
+    config_basename = 'pip.ini'
+
+    legacy_storage_dir = os.path.join(user_dir, 'pip')
+    legacy_config_file = os.path.join(
+        legacy_storage_dir,
+        config_basename,
+    )
+else:
+    bin_py = os.path.join(sys.prefix, 'bin')
+    bin_user = os.path.join(user_site, 'bin')
+
+    config_basename = 'pip.conf'
+
+    legacy_storage_dir = os.path.join(user_dir, '.pip')
+    legacy_config_file = os.path.join(
+        legacy_storage_dir,
+        config_basename,
+    )
+    # Forcing to use /usr/local/bin for standard macOS framework installs
+    # Also log to ~/Library/Logs/ for use with the Console.app log viewer
+    if sys.platform[:6] == 'darwin' and sys.prefix[:16] == '/System/Library/':
+        bin_py = '/usr/local/bin'
+
+site_config_files = [
+    os.path.join(path, config_basename)
+    for path in appdirs.site_config_dirs('pip')
+]
+
+venv_config_file = os.path.join(sys.prefix, config_basename)
+new_config_file = os.path.join(appdirs.user_config_dir("pip"), config_basename)
+
+
+def distutils_scheme(dist_name, user=False, home=None, root=None,
+                     isolated=False, prefix=None):
+    # type:(str, bool, str, str, bool, str) -> dict
+    """
+    Return a distutils install scheme
+    """
+    from distutils.dist import Distribution
+
+    scheme = {}
+
+    if isolated:
+        extra_dist_args = {"script_args": ["--no-user-cfg"]}
+    else:
+        extra_dist_args = {}
+    dist_args = {'name': dist_name}  # type: Dict[str, Union[str, List[str]]]
+    dist_args.update(extra_dist_args)
+
+    d = Distribution(dist_args)
+    # Ignoring, typeshed issue reported python/typeshed/issues/2567
+    d.parse_config_files()
+    # NOTE: Ignoring type since mypy can't find attributes on 'Command'
+    i = d.get_command_obj('install', create=True)  # type: Any
+    assert i is not None
+    # NOTE: setting user or home has the side-effect of creating the home dir
+    # or user base for installations during finalize_options()
+    # ideally, we'd prefer a scheme class that has no side-effects.
+    assert not (user and prefix), "user={} prefix={}".format(user, prefix)
+    i.user = user or i.user
+    if user:
+        i.prefix = ""
+    i.prefix = prefix or i.prefix
+    i.home = home or i.home
+    i.root = root or i.root
+    i.finalize_options()
+    for key in SCHEME_KEYS:
+        scheme[key] = getattr(i, 'install_' + key)
+
+    # install_lib specified in setup.cfg should install *everything*
+    # into there (i.e. it takes precedence over both purelib and
+    # platlib).  Note, i.install_lib is *always* set after
+    # finalize_options(); we only want to override here if the user
+    # has explicitly requested it hence going back to the config
+
+    # Ignoring, typeshed issue reported python/typeshed/issues/2567
+    if 'install_lib' in d.get_option_dict('install'):  # type: ignore
+        scheme.update(dict(purelib=i.install_lib, platlib=i.install_lib))
+
+    if running_under_virtualenv():
+        scheme['headers'] = os.path.join(
+            sys.prefix,
+            'include',
+            'site',
+            'python' + sys.version[:3],
+            dist_name,
+        )
+
+        if root is not None:
+            path_no_drive = os.path.splitdrive(
+                os.path.abspath(scheme["headers"]))[1]
+            scheme["headers"] = os.path.join(
+                root,
+                path_no_drive[1:],
+            )
+
+    return scheme
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/__init__.py
new file mode 100644
index 0000000..7855226
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/__init__.py
@@ -0,0 +1,2 @@
+"""A package that contains models that represent entities.
+"""
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/candidate.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/candidate.py
new file mode 100644
index 0000000..4475458
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/candidate.py
@@ -0,0 +1,31 @@
+from pip._vendor.packaging.version import parse as parse_version
+
+from pip._internal.utils.models import KeyBasedCompareMixin
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from pip._vendor.packaging.version import _BaseVersion  # noqa: F401
+    from pip._internal.models.link import Link  # noqa: F401
+    from typing import Any, Union  # noqa: F401
+
+
+class InstallationCandidate(KeyBasedCompareMixin):
+    """Represents a potential "candidate" for installation.
+    """
+
+    def __init__(self, project, version, location):
+        # type: (Any, str, Link) -> None
+        self.project = project
+        self.version = parse_version(version)  # type: _BaseVersion
+        self.location = location
+
+        super(InstallationCandidate, self).__init__(
+            key=(self.project, self.version, self.location),
+            defining_class=InstallationCandidate
+        )
+
+    def __repr__(self):
+        # type: () -> str
+        return "<InstallationCandidate({!r}, {!r}, {!r})>".format(
+            self.project, self.version, self.location,
+        )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/format_control.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/format_control.py
new file mode 100644
index 0000000..971a391
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/format_control.py
@@ -0,0 +1,73 @@
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Set, FrozenSet  # noqa: F401
+
+
+class FormatControl(object):
+    """Helper for managing formats from which a package can be installed.
+    """
+
+    def __init__(self, no_binary=None, only_binary=None):
+        # type: (Optional[Set], Optional[Set]) -> None
+        if no_binary is None:
+            no_binary = set()
+        if only_binary is None:
+            only_binary = set()
+
+        self.no_binary = no_binary
+        self.only_binary = only_binary
+
+    def __eq__(self, other):
+        return self.__dict__ == other.__dict__
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __repr__(self):
+        return "{}({}, {})".format(
+            self.__class__.__name__,
+            self.no_binary,
+            self.only_binary
+        )
+
+    @staticmethod
+    def handle_mutual_excludes(value, target, other):
+        # type: (str, Optional[Set], Optional[Set]) -> None
+        new = value.split(',')
+        while ':all:' in new:
+            other.clear()
+            target.clear()
+            target.add(':all:')
+            del new[:new.index(':all:') + 1]
+            # Without a none, we want to discard everything as :all: covers it
+            if ':none:' not in new:
+                return
+        for name in new:
+            if name == ':none:':
+                target.clear()
+                continue
+            name = canonicalize_name(name)
+            other.discard(name)
+            target.add(name)
+
+    def get_allowed_formats(self, canonical_name):
+        # type: (str) -> FrozenSet
+        result = {"binary", "source"}
+        if canonical_name in self.only_binary:
+            result.discard('source')
+        elif canonical_name in self.no_binary:
+            result.discard('binary')
+        elif ':all:' in self.only_binary:
+            result.discard('source')
+        elif ':all:' in self.no_binary:
+            result.discard('binary')
+        return frozenset(result)
+
+    def disallow_binaries(self):
+        # type: () -> None
+        self.handle_mutual_excludes(
+            ':all:', self.no_binary, self.only_binary,
+        )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/index.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/index.py
new file mode 100644
index 0000000..ead1efb
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/index.py
@@ -0,0 +1,31 @@
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+
+class PackageIndex(object):
+    """Represents a Package Index and provides easier access to endpoints
+    """
+
+    def __init__(self, url, file_storage_domain):
+        # type: (str, str) -> None
+        super(PackageIndex, self).__init__()
+        self.url = url
+        self.netloc = urllib_parse.urlsplit(url).netloc
+        self.simple_url = self._url_for_path('simple')
+        self.pypi_url = self._url_for_path('pypi')
+
+        # This is part of a temporary hack used to block installs of PyPI
+        # packages which depend on external urls only necessary until PyPI can
+        # block such packages themselves
+        self.file_storage_domain = file_storage_domain
+
+    def _url_for_path(self, path):
+        # type: (str) -> str
+        return urllib_parse.urljoin(self.url, path)
+
+
+PyPI = PackageIndex(
+    'https://pypi.org/', file_storage_domain='files.pythonhosted.org'
+)
+TestPyPI = PackageIndex(
+    'https://test.pypi.org/', file_storage_domain='test-files.pythonhosted.org'
+)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/link.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/link.py
new file mode 100644
index 0000000..ad2f93e
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/models/link.py
@@ -0,0 +1,163 @@
+import posixpath
+import re
+
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+from pip._internal.download import path_to_url
+from pip._internal.utils.misc import (
+    WHEEL_EXTENSION, redact_password_from_url, splitext,
+)
+from pip._internal.utils.models import KeyBasedCompareMixin
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Tuple, Union, Text  # noqa: F401
+    from pip._internal.index import HTMLPage  # noqa: F401
+
+
+class Link(KeyBasedCompareMixin):
+    """Represents a parsed link from a Package Index's simple URL
+    """
+
+    def __init__(self, url, comes_from=None, requires_python=None):
+        # type: (str, Optional[Union[str, HTMLPage]], Optional[str]) -> None
+        """
+        url:
+            url of the resource pointed to (href of the link)
+        comes_from:
+            instance of HTMLPage where the link was found, or string.
+        requires_python:
+            String containing the `Requires-Python` metadata field, specified
+            in PEP 345. This may be specified by a data-requires-python
+            attribute in the HTML link tag, as described in PEP 503.
+        """
+
+        # url can be a UNC windows share
+        if url.startswith('\\\\'):
+            url = path_to_url(url)
+
+        self.url = url
+        self.comes_from = comes_from
+        self.requires_python = requires_python if requires_python else None
+
+        super(Link, self).__init__(
+            key=(self.url),
+            defining_class=Link
+        )
+
+    def __str__(self):
+        if self.requires_python:
+            rp = ' (requires-python:%s)' % self.requires_python
+        else:
+            rp = ''
+        if self.comes_from:
+            return '%s (from %s)%s' % (redact_password_from_url(self.url),
+                                       self.comes_from, rp)
+        else:
+            return redact_password_from_url(str(self.url))
+
+    def __repr__(self):
+        return '<Link %s>' % self
+
+    @property
+    def filename(self):
+        # type: () -> str
+        _, netloc, path, _, _ = urllib_parse.urlsplit(self.url)
+        name = posixpath.basename(path.rstrip('/')) or netloc
+        name = urllib_parse.unquote(name)
+        assert name, ('URL %r produced no filename' % self.url)
+        return name
+
+    @property
+    def scheme(self):
+        # type: () -> str
+        return urllib_parse.urlsplit(self.url)[0]
+
+    @property
+    def netloc(self):
+        # type: () -> str
+        return urllib_parse.urlsplit(self.url)[1]
+
+    @property
+    def path(self):
+        # type: () -> str
+        return urllib_parse.unquote(urllib_parse.urlsplit(self.url)[2])
+
+    def splitext(self):
+        # type: () -> Tuple[str, str]
+        return splitext(posixpath.basename(self.path.rstrip('/')))
+
+    @property
+    def ext(self):
+        # type: () -> str
+        return self.splitext()[1]
+
+    @property
+    def url_without_fragment(self):
+        # type: () -> str
+        scheme, netloc, path, query, fragment = urllib_parse.urlsplit(self.url)
+        return urllib_parse.urlunsplit((scheme, netloc, path, query, None))
+
+    _egg_fragment_re = re.compile(r'[#&]egg=([^&]*)')
+
+    @property
+    def egg_fragment(self):
+        # type: () -> Optional[str]
+        match = self._egg_fragment_re.search(self.url)
+        if not match:
+            return None
+        return match.group(1)
+
+    _subdirectory_fragment_re = re.compile(r'[#&]subdirectory=([^&]*)')
+
+    @property
+    def subdirectory_fragment(self):
+        # type: () -> Optional[str]
+        match = self._subdirectory_fragment_re.search(self.url)
+        if not match:
+            return None
+        return match.group(1)
+
+    _hash_re = re.compile(
+        r'(sha1|sha224|sha384|sha256|sha512|md5)=([a-f0-9]+)'
+    )
+
+    @property
+    def hash(self):
+        # type: () -> Optional[str]
+        match = self._hash_re.search(self.url)
+        if match:
+            return match.group(2)
+        return None
+
+    @property
+    def hash_name(self):
+        # type: () -> Optional[str]
+        match = self._hash_re.search(self.url)
+        if match:
+            return match.group(1)
+        return None
+
+    @property
+    def show_url(self):
+        # type: () -> Optional[str]
+        return posixpath.basename(self.url.split('#', 1)[0].split('?', 1)[0])
+
+    @property
+    def is_wheel(self):
+        # type: () -> bool
+        return self.ext == WHEEL_EXTENSION
+
+    @property
+    def is_artifact(self):
+        # type: () -> bool
+        """
+        Determines if this points to an actual artifact (e.g. a tarball) or if
+        it points to an "abstract" thing like a path or a VCS location.
+        """
+        from pip._internal.vcs import vcs
+
+        if self.scheme in vcs.all_schemes:
+            return False
+
+        return True
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/__init__.py
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/check.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/check.py
new file mode 100644
index 0000000..0b56eda
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/check.py
@@ -0,0 +1,155 @@
+"""Validation of dependencies of packages
+"""
+
+import logging
+from collections import namedtuple
+
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import RequirementParseError
+
+from pip._internal.operations.prepare import make_abstract_dist
+from pip._internal.utils.misc import get_installed_distributions
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+logger = logging.getLogger(__name__)
+
+if MYPY_CHECK_RUNNING:
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+    from typing import (  # noqa: F401
+        Any, Callable, Dict, Optional, Set, Tuple, List
+    )
+
+    # Shorthands
+    PackageSet = Dict[str, 'PackageDetails']
+    Missing = Tuple[str, Any]
+    Conflicting = Tuple[str, str, Any]
+
+    MissingDict = Dict[str, List[Missing]]
+    ConflictingDict = Dict[str, List[Conflicting]]
+    CheckResult = Tuple[MissingDict, ConflictingDict]
+
+PackageDetails = namedtuple('PackageDetails', ['version', 'requires'])
+
+
+def create_package_set_from_installed(**kwargs):
+    # type: (**Any) -> Tuple[PackageSet, bool]
+    """Converts a list of distributions into a PackageSet.
+    """
+    # Default to using all packages installed on the system
+    if kwargs == {}:
+        kwargs = {"local_only": False, "skip": ()}
+
+    package_set = {}
+    problems = False
+    for dist in get_installed_distributions(**kwargs):
+        name = canonicalize_name(dist.project_name)
+        try:
+            package_set[name] = PackageDetails(dist.version, dist.requires())
+        except RequirementParseError as e:
+            # Don't crash on broken metadata
+            logging.warning("Error parsing requirements for %s: %s", name, e)
+            problems = True
+    return package_set, problems
+
+
+def check_package_set(package_set, should_ignore=None):
+    # type: (PackageSet, Optional[Callable[[str], bool]]) -> CheckResult
+    """Check if a package set is consistent
+
+    If should_ignore is passed, it should be a callable that takes a
+    package name and returns a boolean.
+    """
+    if should_ignore is None:
+        def should_ignore(name):
+            return False
+
+    missing = dict()
+    conflicting = dict()
+
+    for package_name in package_set:
+        # Info about dependencies of package_name
+        missing_deps = set()  # type: Set[Missing]
+        conflicting_deps = set()  # type: Set[Conflicting]
+
+        if should_ignore(package_name):
+            continue
+
+        for req in package_set[package_name].requires:
+            name = canonicalize_name(req.project_name)  # type: str
+
+            # Check if it's missing
+            if name not in package_set:
+                missed = True
+                if req.marker is not None:
+                    missed = req.marker.evaluate()
+                if missed:
+                    missing_deps.add((name, req))
+                continue
+
+            # Check if there's a conflict
+            version = package_set[name].version  # type: str
+            if not req.specifier.contains(version, prereleases=True):
+                conflicting_deps.add((name, version, req))
+
+        if missing_deps:
+            missing[package_name] = sorted(missing_deps, key=str)
+        if conflicting_deps:
+            conflicting[package_name] = sorted(conflicting_deps, key=str)
+
+    return missing, conflicting
+
+
+def check_install_conflicts(to_install):
+    # type: (List[InstallRequirement]) -> Tuple[PackageSet, CheckResult]
+    """For checking if the dependency graph would be consistent after \
+    installing given requirements
+    """
+    # Start from the current state
+    package_set, _ = create_package_set_from_installed()
+    # Install packages
+    would_be_installed = _simulate_installation_of(to_install, package_set)
+
+    # Only warn about directly-dependent packages; create a whitelist of them
+    whitelist = _create_whitelist(would_be_installed, package_set)
+
+    return (
+        package_set,
+        check_package_set(
+            package_set, should_ignore=lambda name: name not in whitelist
+        )
+    )
+
+
+def _simulate_installation_of(to_install, package_set):
+    # type: (List[InstallRequirement], PackageSet) -> Set[str]
+    """Computes the version of packages after installing to_install.
+    """
+
+    # Keep track of packages that were installed
+    installed = set()
+
+    # Modify it as installing requirement_set would (assuming no errors)
+    for inst_req in to_install:
+        dist = make_abstract_dist(inst_req).dist()
+        name = canonicalize_name(dist.key)
+        package_set[name] = PackageDetails(dist.version, dist.requires())
+
+        installed.add(name)
+
+    return installed
+
+
+def _create_whitelist(would_be_installed, package_set):
+    # type: (Set[str], PackageSet) -> Set[str]
+    packages_affected = set(would_be_installed)
+
+    for package_name in package_set:
+        if package_name in packages_affected:
+            continue
+
+        for req in package_set[package_name].requires:
+            if canonicalize_name(req.name) in packages_affected:
+                packages_affected.add(package_name)
+                break
+
+    return packages_affected
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/freeze.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/freeze.py
new file mode 100644
index 0000000..388bb73
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/freeze.py
@@ -0,0 +1,247 @@
+from __future__ import absolute_import
+
+import collections
+import logging
+import os
+import re
+
+from pip._vendor import six
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import RequirementParseError
+
+from pip._internal.exceptions import BadCommand, InstallationError
+from pip._internal.req.constructors import (
+    install_req_from_editable, install_req_from_line,
+)
+from pip._internal.req.req_file import COMMENT_RE
+from pip._internal.utils.misc import (
+    dist_is_editable, get_installed_distributions,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Iterator, Optional, List, Container, Set, Dict, Tuple, Iterable, Union
+    )
+    from pip._internal.cache import WheelCache  # noqa: F401
+    from pip._vendor.pkg_resources import (  # noqa: F401
+        Distribution, Requirement
+    )
+
+    RequirementInfo = Tuple[Optional[Union[str, Requirement]], bool, List[str]]
+
+
+logger = logging.getLogger(__name__)
+
+
+def freeze(
+    requirement=None,  # type: Optional[List[str]]
+    find_links=None,  # type: Optional[List[str]]
+    local_only=None,  # type: Optional[bool]
+    user_only=None,  # type: Optional[bool]
+    skip_regex=None,  # type: Optional[str]
+    isolated=False,  # type: bool
+    wheel_cache=None,  # type: Optional[WheelCache]
+    exclude_editable=False,  # type: bool
+    skip=()  # type: Container[str]
+):
+    # type: (...) -> Iterator[str]
+    find_links = find_links or []
+    skip_match = None
+
+    if skip_regex:
+        skip_match = re.compile(skip_regex).search
+
+    for link in find_links:
+        yield '-f %s' % link
+    installations = {}  # type: Dict[str, FrozenRequirement]
+    for dist in get_installed_distributions(local_only=local_only,
+                                            skip=(),
+                                            user_only=user_only):
+        try:
+            req = FrozenRequirement.from_dist(dist)
+        except RequirementParseError:
+            logger.warning(
+                "Could not parse requirement: %s",
+                dist.project_name
+            )
+            continue
+        if exclude_editable and req.editable:
+            continue
+        installations[req.name] = req
+
+    if requirement:
+        # the options that don't get turned into an InstallRequirement
+        # should only be emitted once, even if the same option is in multiple
+        # requirements files, so we need to keep track of what has been emitted
+        # so that we don't emit it again if it's seen again
+        emitted_options = set()  # type: Set[str]
+        # keep track of which files a requirement is in so that we can
+        # give an accurate warning if a requirement appears multiple times.
+        req_files = collections.defaultdict(list)  # type: Dict[str, List[str]]
+        for req_file_path in requirement:
+            with open(req_file_path) as req_file:
+                for line in req_file:
+                    if (not line.strip() or
+                            line.strip().startswith('#') or
+                            (skip_match and skip_match(line)) or
+                            line.startswith((
+                                '-r', '--requirement',
+                                '-Z', '--always-unzip',
+                                '-f', '--find-links',
+                                '-i', '--index-url',
+                                '--pre',
+                                '--trusted-host',
+                                '--process-dependency-links',
+                                '--extra-index-url'))):
+                        line = line.rstrip()
+                        if line not in emitted_options:
+                            emitted_options.add(line)
+                            yield line
+                        continue
+
+                    if line.startswith('-e') or line.startswith('--editable'):
+                        if line.startswith('-e'):
+                            line = line[2:].strip()
+                        else:
+                            line = line[len('--editable'):].strip().lstrip('=')
+                        line_req = install_req_from_editable(
+                            line,
+                            isolated=isolated,
+                            wheel_cache=wheel_cache,
+                        )
+                    else:
+                        line_req = install_req_from_line(
+                            COMMENT_RE.sub('', line).strip(),
+                            isolated=isolated,
+                            wheel_cache=wheel_cache,
+                        )
+
+                    if not line_req.name:
+                        logger.info(
+                            "Skipping line in requirement file [%s] because "
+                            "it's not clear what it would install: %s",
+                            req_file_path, line.strip(),
+                        )
+                        logger.info(
+                            "  (add #egg=PackageName to the URL to avoid"
+                            " this warning)"
+                        )
+                    elif line_req.name not in installations:
+                        # either it's not installed, or it is installed
+                        # but has been processed already
+                        if not req_files[line_req.name]:
+                            logger.warning(
+                                "Requirement file [%s] contains %s, but "
+                                "package %r is not installed",
+                                req_file_path,
+                                COMMENT_RE.sub('', line).strip(), line_req.name
+                            )
+                        else:
+                            req_files[line_req.name].append(req_file_path)
+                    else:
+                        yield str(installations[line_req.name]).rstrip()
+                        del installations[line_req.name]
+                        req_files[line_req.name].append(req_file_path)
+
+        # Warn about requirements that were included multiple times (in a
+        # single requirements file or in different requirements files).
+        for name, files in six.iteritems(req_files):
+            if len(files) > 1:
+                logger.warning("Requirement %s included multiple times [%s]",
+                               name, ', '.join(sorted(set(files))))
+
+        yield(
+            '## The following requirements were added by '
+            'pip freeze:'
+        )
+    for installation in sorted(
+            installations.values(), key=lambda x: x.name.lower()):
+        if canonicalize_name(installation.name) not in skip:
+            yield str(installation).rstrip()
+
+
+def get_requirement_info(dist):
+    # type: (Distribution) -> RequirementInfo
+    """
+    Compute and return values (req, editable, comments) for use in
+    FrozenRequirement.from_dist().
+    """
+    if not dist_is_editable(dist):
+        return (None, False, [])
+
+    location = os.path.normcase(os.path.abspath(dist.location))
+
+    from pip._internal.vcs import vcs, RemoteNotFoundError
+    vc_type = vcs.get_backend_type(location)
+
+    if not vc_type:
+        req = dist.as_requirement()
+        logger.debug(
+            'No VCS found for editable requirement {!r} in: {!r}', req,
+            location,
+        )
+        comments = [
+            '# Editable install with no version control ({})'.format(req)
+        ]
+        return (location, True, comments)
+
+    try:
+        req = vc_type.get_src_requirement(location, dist.project_name)
+    except RemoteNotFoundError:
+        req = dist.as_requirement()
+        comments = [
+            '# Editable {} install with no remote ({})'.format(
+                vc_type.__name__, req,
+            )
+        ]
+        return (location, True, comments)
+
+    except BadCommand:
+        logger.warning(
+            'cannot determine version of editable source in %s '
+            '(%s command not found in path)',
+            location,
+            vc_type.name,
+        )
+        return (None, True, [])
+
+    except InstallationError as exc:
+        logger.warning(
+            "Error when trying to get requirement for VCS system %s, "
+            "falling back to uneditable format", exc
+        )
+    else:
+        if req is not None:
+            return (req, True, [])
+
+    logger.warning(
+        'Could not determine repository location of %s', location
+    )
+    comments = ['## !! Could not determine repository location']
+
+    return (None, False, comments)
+
+
+class FrozenRequirement(object):
+    def __init__(self, name, req, editable, comments=()):
+        # type: (str, Union[str, Requirement], bool, Iterable[str]) -> None
+        self.name = name
+        self.req = req
+        self.editable = editable
+        self.comments = comments
+
+    @classmethod
+    def from_dist(cls, dist):
+        # type: (Distribution) -> FrozenRequirement
+        req, editable, comments = get_requirement_info(dist)
+        if req is None:
+            req = dist.as_requirement()
+
+        return cls(dist.project_name, req, editable, comments=comments)
+
+    def __str__(self):
+        req = self.req
+        if self.editable:
+            req = '-e %s' % req
+        return '\n'.join(list(self.comments) + [str(req)]) + '\n'
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/prepare.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/prepare.py
new file mode 100644
index 0000000..4f31dd5
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/operations/prepare.py
@@ -0,0 +1,413 @@
+"""Prepares a distribution for installation
+"""
+
+import logging
+import os
+
+from pip._vendor import pkg_resources, requests
+
+from pip._internal.build_env import BuildEnvironment
+from pip._internal.download import (
+    is_dir_url, is_file_url, is_vcs_url, unpack_url, url_to_path,
+)
+from pip._internal.exceptions import (
+    DirectoryUrlHashUnsupported, HashUnpinned, InstallationError,
+    PreviousBuildDirError, VcsHashUnsupported,
+)
+from pip._internal.utils.compat import expanduser
+from pip._internal.utils.hashes import MissingHashes
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import display_path, normalize_path
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.vcs import vcs
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Optional  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+    from pip._internal.index import PackageFinder  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+    from pip._internal.req.req_tracker import RequirementTracker  # noqa: F401
+
+logger = logging.getLogger(__name__)
+
+
+def make_abstract_dist(req):
+    # type: (InstallRequirement) -> DistAbstraction
+    """Factory to make an abstract dist object.
+
+    Preconditions: Either an editable req with a source_dir, or satisfied_by or
+    a wheel link, or a non-editable req with a source_dir.
+
+    :return: A concrete DistAbstraction.
+    """
+    if req.editable:
+        return IsSDist(req)
+    elif req.link and req.link.is_wheel:
+        return IsWheel(req)
+    else:
+        return IsSDist(req)
+
+
+class DistAbstraction(object):
+    """Abstracts out the wheel vs non-wheel Resolver.resolve() logic.
+
+    The requirements for anything installable are as follows:
+     - we must be able to determine the requirement name
+       (or we can't correctly handle the non-upgrade case).
+     - we must be able to generate a list of run-time dependencies
+       without installing any additional packages (or we would
+       have to either burn time by doing temporary isolated installs
+       or alternatively violate pips 'don't start installing unless
+       all requirements are available' rule - neither of which are
+       desirable).
+     - for packages with setup requirements, we must also be able
+       to determine their requirements without installing additional
+       packages (for the same reason as run-time dependencies)
+     - we must be able to create a Distribution object exposing the
+       above metadata.
+    """
+
+    def __init__(self, req):
+        # type: (InstallRequirement) -> None
+        self.req = req  # type: InstallRequirement
+
+    def dist(self):
+        # type: () -> Any
+        """Return a setuptools Dist object."""
+        raise NotImplementedError
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        """Ensure that we can get a Dist for this requirement."""
+        raise NotImplementedError
+
+
+class IsWheel(DistAbstraction):
+
+    def dist(self):
+        # type: () -> pkg_resources.Distribution
+        return list(pkg_resources.find_distributions(
+            self.req.source_dir))[0]
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        # FIXME:https://github.com/pypa/pip/issues/1112
+        pass
+
+
+class IsSDist(DistAbstraction):
+
+    def dist(self):
+        return self.req.get_dist()
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> None
+        # Prepare for building. We need to:
+        #   1. Load pyproject.toml (if it exists)
+        #   2. Set up the build environment
+
+        self.req.load_pyproject_toml()
+        should_isolate = self.req.use_pep517 and build_isolation
+
+        def _raise_conflicts(conflicting_with, conflicting_reqs):
+            raise InstallationError(
+                "Some build dependencies for %s conflict with %s: %s." % (
+                    self.req, conflicting_with, ', '.join(
+                        '%s is incompatible with %s' % (installed, wanted)
+                        for installed, wanted in sorted(conflicting))))
+
+        if should_isolate:
+            # Isolate in a BuildEnvironment and install the build-time
+            # requirements.
+            self.req.build_env = BuildEnvironment()
+            self.req.build_env.install_requirements(
+                finder, self.req.pyproject_requires, 'overlay',
+                "Installing build dependencies"
+            )
+            conflicting, missing = self.req.build_env.check_requirements(
+                self.req.requirements_to_check
+            )
+            if conflicting:
+                _raise_conflicts("PEP 517/518 supported requirements",
+                                 conflicting)
+            if missing:
+                logger.warning(
+                    "Missing build requirements in pyproject.toml for %s.",
+                    self.req,
+                )
+                logger.warning(
+                    "The project does not specify a build backend, and "
+                    "pip cannot fall back to setuptools without %s.",
+                    " and ".join(map(repr, sorted(missing)))
+                )
+            # Install any extra build dependencies that the backend requests.
+            # This must be done in a second pass, as the pyproject.toml
+            # dependencies must be installed before we can call the backend.
+            with self.req.build_env:
+                # We need to have the env active when calling the hook.
+                self.req.spin_message = "Getting requirements to build wheel"
+                reqs = self.req.pep517_backend.get_requires_for_build_wheel()
+            conflicting, missing = self.req.build_env.check_requirements(reqs)
+            if conflicting:
+                _raise_conflicts("the backend dependencies", conflicting)
+            self.req.build_env.install_requirements(
+                finder, missing, 'normal',
+                "Installing backend dependencies"
+            )
+
+        self.req.prepare_metadata()
+        self.req.assert_source_matches_version()
+
+
+class Installed(DistAbstraction):
+
+    def dist(self):
+        # type: () -> pkg_resources.Distribution
+        return self.req.satisfied_by
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        pass
+
+
+class RequirementPreparer(object):
+    """Prepares a Requirement
+    """
+
+    def __init__(
+        self,
+        build_dir,  # type: str
+        download_dir,  # type: Optional[str]
+        src_dir,  # type: str
+        wheel_download_dir,  # type: Optional[str]
+        progress_bar,  # type: str
+        build_isolation,  # type: bool
+        req_tracker  # type: RequirementTracker
+    ):
+        # type: (...) -> None
+        super(RequirementPreparer, self).__init__()
+
+        self.src_dir = src_dir
+        self.build_dir = build_dir
+        self.req_tracker = req_tracker
+
+        # Where still packed archives should be written to. If None, they are
+        # not saved, and are deleted immediately after unpacking.
+        self.download_dir = download_dir
+
+        # Where still-packed .whl files should be written to. If None, they are
+        # written to the download_dir parameter. Separate to download_dir to
+        # permit only keeping wheel archives for pip wheel.
+        if wheel_download_dir:
+            wheel_download_dir = normalize_path(wheel_download_dir)
+        self.wheel_download_dir = wheel_download_dir
+
+        # NOTE
+        # download_dir and wheel_download_dir overlap semantically and may
+        # be combined if we're willing to have non-wheel archives present in
+        # the wheelhouse output by 'pip wheel'.
+
+        self.progress_bar = progress_bar
+
+        # Is build isolation allowed?
+        self.build_isolation = build_isolation
+
+    @property
+    def _download_should_save(self):
+        # type: () -> bool
+        # TODO: Modify to reduce indentation needed
+        if self.download_dir:
+            self.download_dir = expanduser(self.download_dir)
+            if os.path.exists(self.download_dir):
+                return True
+            else:
+                logger.critical('Could not find download directory')
+                raise InstallationError(
+                    "Could not find or access download directory '%s'"
+                    % display_path(self.download_dir))
+        return False
+
+    def prepare_linked_requirement(
+        self,
+        req,  # type: InstallRequirement
+        session,  # type: PipSession
+        finder,  # type: PackageFinder
+        upgrade_allowed,  # type: bool
+        require_hashes  # type: bool
+    ):
+        # type: (...) -> DistAbstraction
+        """Prepare a requirement that would be obtained from req.link
+        """
+        # TODO: Breakup into smaller functions
+        if req.link and req.link.scheme == 'file':
+            path = url_to_path(req.link.url)
+            logger.info('Processing %s', display_path(path))
+        else:
+            logger.info('Collecting %s', req)
+
+        with indent_log():
+            # @@ if filesystem packages are not marked
+            # editable in a req, a non deterministic error
+            # occurs when the script attempts to unpack the
+            # build directory
+            req.ensure_has_source_dir(self.build_dir)
+            # If a checkout exists, it's unwise to keep going.  version
+            # inconsistencies are logged later, but do not fail the
+            # installation.
+            # FIXME: this won't upgrade when there's an existing
+            # package unpacked in `req.source_dir`
+            # package unpacked in `req.source_dir`
+            if os.path.exists(os.path.join(req.source_dir, 'setup.py')):
+                raise PreviousBuildDirError(
+                    "pip can't proceed with requirements '%s' due to a"
+                    " pre-existing build directory (%s). This is "
+                    "likely due to a previous installation that failed"
+                    ". pip is being responsible and not assuming it "
+                    "can delete this. Please delete it and try again."
+                    % (req, req.source_dir)
+                )
+            req.populate_link(finder, upgrade_allowed, require_hashes)
+
+            # We can't hit this spot and have populate_link return None.
+            # req.satisfied_by is None here (because we're
+            # guarded) and upgrade has no impact except when satisfied_by
+            # is not None.
+            # Then inside find_requirement existing_applicable -> False
+            # If no new versions are found, DistributionNotFound is raised,
+            # otherwise a result is guaranteed.
+            assert req.link
+            link = req.link
+
+            # Now that we have the real link, we can tell what kind of
+            # requirements we have and raise some more informative errors
+            # than otherwise. (For example, we can raise VcsHashUnsupported
+            # for a VCS URL rather than HashMissing.)
+            if require_hashes:
+                # We could check these first 2 conditions inside
+                # unpack_url and save repetition of conditions, but then
+                # we would report less-useful error messages for
+                # unhashable requirements, complaining that there's no
+                # hash provided.
+                if is_vcs_url(link):
+                    raise VcsHashUnsupported()
+                elif is_file_url(link) and is_dir_url(link):
+                    raise DirectoryUrlHashUnsupported()
+                if not req.original_link and not req.is_pinned:
+                    # Unpinned packages are asking for trouble when a new
+                    # version is uploaded. This isn't a security check, but
+                    # it saves users a surprising hash mismatch in the
+                    # future.
+                    #
+                    # file:/// URLs aren't pinnable, so don't complain
+                    # about them not being pinned.
+                    raise HashUnpinned()
+
+            hashes = req.hashes(trust_internet=not require_hashes)
+            if require_hashes and not hashes:
+                # Known-good hashes are missing for this requirement, so
+                # shim it with a facade object that will provoke hash
+                # computation and then raise a HashMissing exception
+                # showing the user what the hash should be.
+                hashes = MissingHashes()
+
+            try:
+                download_dir = self.download_dir
+                # We always delete unpacked sdists after pip ran.
+                autodelete_unpacked = True
+                if req.link.is_wheel and self.wheel_download_dir:
+                    # when doing 'pip wheel` we download wheels to a
+                    # dedicated dir.
+                    download_dir = self.wheel_download_dir
+                if req.link.is_wheel:
+                    if download_dir:
+                        # When downloading, we only unpack wheels to get
+                        # metadata.
+                        autodelete_unpacked = True
+                    else:
+                        # When installing a wheel, we use the unpacked
+                        # wheel.
+                        autodelete_unpacked = False
+                unpack_url(
+                    req.link, req.source_dir,
+                    download_dir, autodelete_unpacked,
+                    session=session, hashes=hashes,
+                    progress_bar=self.progress_bar
+                )
+            except requests.HTTPError as exc:
+                logger.critical(
+                    'Could not install requirement %s because of error %s',
+                    req,
+                    exc,
+                )
+                raise InstallationError(
+                    'Could not install requirement %s because of HTTP '
+                    'error %s for URL %s' %
+                    (req, exc, req.link)
+                )
+            abstract_dist = make_abstract_dist(req)
+            with self.req_tracker.track(req):
+                abstract_dist.prep_for_dist(finder, self.build_isolation)
+            if self._download_should_save:
+                # Make a .zip of the source_dir we already created.
+                if req.link.scheme in vcs.all_schemes:
+                    req.archive(self.download_dir)
+        return abstract_dist
+
+    def prepare_editable_requirement(
+        self,
+        req,  # type: InstallRequirement
+        require_hashes,  # type: bool
+        use_user_site,  # type: bool
+        finder  # type: PackageFinder
+    ):
+        # type: (...) -> DistAbstraction
+        """Prepare an editable requirement
+        """
+        assert req.editable, "cannot prepare a non-editable req as editable"
+
+        logger.info('Obtaining %s', req)
+
+        with indent_log():
+            if require_hashes:
+                raise InstallationError(
+                    'The editable requirement %s cannot be installed when '
+                    'requiring hashes, because there is no single file to '
+                    'hash.' % req
+                )
+            req.ensure_has_source_dir(self.src_dir)
+            req.update_editable(not self._download_should_save)
+
+            abstract_dist = make_abstract_dist(req)
+            with self.req_tracker.track(req):
+                abstract_dist.prep_for_dist(finder, self.build_isolation)
+
+            if self._download_should_save:
+                req.archive(self.download_dir)
+            req.check_if_exists(use_user_site)
+
+        return abstract_dist
+
+    def prepare_installed_requirement(self, req, require_hashes, skip_reason):
+        # type: (InstallRequirement, bool, Optional[str]) -> DistAbstraction
+        """Prepare an already-installed requirement
+        """
+        assert req.satisfied_by, "req should have been satisfied but isn't"
+        assert skip_reason is not None, (
+            "did not get skip reason skipped but req.satisfied_by "
+            "is set to %r" % (req.satisfied_by,)
+        )
+        logger.info(
+            'Requirement %s: %s (%s)',
+            skip_reason, req, req.satisfied_by.version
+        )
+        with indent_log():
+            if require_hashes:
+                logger.debug(
+                    'Since it is already installed, we are trusting this '
+                    'package without checking its hash. To ensure a '
+                    'completely repeatable environment, install into an '
+                    'empty virtualenv.'
+                )
+            abstract_dist = Installed(req)
+
+        return abstract_dist
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pep425tags.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pep425tags.py
new file mode 100644
index 0000000..1e782d1
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pep425tags.py
@@ -0,0 +1,381 @@
+"""Generate and work with PEP 425 Compatibility Tags."""
+from __future__ import absolute_import
+
+import distutils.util
+import logging
+import platform
+import re
+import sys
+import sysconfig
+import warnings
+from collections import OrderedDict
+
+import pip._internal.utils.glibc
+from pip._internal.utils.compat import get_extension_suffixes
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Tuple, Callable, List, Optional, Union, Dict
+    )
+
+    Pep425Tag = Tuple[str, str, str]
+
+logger = logging.getLogger(__name__)
+
+_osx_arch_pat = re.compile(r'(.+)_(\d+)_(\d+)_(.+)')
+
+
+def get_config_var(var):
+    # type: (str) -> Optional[str]
+    try:
+        return sysconfig.get_config_var(var)
+    except IOError as e:  # Issue #1074
+        warnings.warn("{}".format(e), RuntimeWarning)
+        return None
+
+
+def get_abbr_impl():
+    # type: () -> str
+    """Return abbreviated implementation name."""
+    if hasattr(sys, 'pypy_version_info'):
+        pyimpl = 'pp'
+    elif sys.platform.startswith('java'):
+        pyimpl = 'jy'
+    elif sys.platform == 'cli':
+        pyimpl = 'ip'
+    else:
+        pyimpl = 'cp'
+    return pyimpl
+
+
+def get_impl_ver():
+    # type: () -> str
+    """Return implementation version."""
+    impl_ver = get_config_var("py_version_nodot")
+    if not impl_ver or get_abbr_impl() == 'pp':
+        impl_ver = ''.join(map(str, get_impl_version_info()))
+    return impl_ver
+
+
+def get_impl_version_info():
+    # type: () -> Tuple[int, ...]
+    """Return sys.version_info-like tuple for use in decrementing the minor
+    version."""
+    if get_abbr_impl() == 'pp':
+        # as per https://github.com/pypa/pip/issues/2882
+        # attrs exist only on pypy
+        return (sys.version_info[0],
+                sys.pypy_version_info.major,  # type: ignore
+                sys.pypy_version_info.minor)  # type: ignore
+    else:
+        return sys.version_info[0], sys.version_info[1]
+
+
+def get_impl_tag():
+    # type: () -> str
+    """
+    Returns the Tag for this specific implementation.
+    """
+    return "{}{}".format(get_abbr_impl(), get_impl_ver())
+
+
+def get_flag(var, fallback, expected=True, warn=True):
+    # type: (str, Callable[..., bool], Union[bool, int], bool) -> bool
+    """Use a fallback method for determining SOABI flags if the needed config
+    var is unset or unavailable."""
+    val = get_config_var(var)
+    if val is None:
+        if warn:
+            logger.debug("Config variable '%s' is unset, Python ABI tag may "
+                         "be incorrect", var)
+        return fallback()
+    return val == expected
+
+
+def get_abi_tag():
+    # type: () -> Optional[str]
+    """Return the ABI tag based on SOABI (if available) or emulate SOABI
+    (CPython 2, PyPy)."""
+    soabi = get_config_var('SOABI')
+    impl = get_abbr_impl()
+    if not soabi and impl in {'cp', 'pp'} and hasattr(sys, 'maxunicode'):
+        d = ''
+        m = ''
+        u = ''
+        if get_flag('Py_DEBUG',
+                    lambda: hasattr(sys, 'gettotalrefcount'),
+                    warn=(impl == 'cp')):
+            d = 'd'
+        if get_flag('WITH_PYMALLOC',
+                    lambda: impl == 'cp',
+                    warn=(impl == 'cp')):
+            m = 'm'
+        if get_flag('Py_UNICODE_SIZE',
+                    lambda: sys.maxunicode == 0x10ffff,
+                    expected=4,
+                    warn=(impl == 'cp' and
+                          sys.version_info < (3, 3))) \
+                and sys.version_info < (3, 3):
+            u = 'u'
+        abi = '%s%s%s%s%s' % (impl, get_impl_ver(), d, m, u)
+    elif soabi and soabi.startswith('cpython-'):
+        abi = 'cp' + soabi.split('-')[1]
+    elif soabi:
+        abi = soabi.replace('.', '_').replace('-', '_')
+    else:
+        abi = None
+    return abi
+
+
+def _is_running_32bit():
+    # type: () -> bool
+    return sys.maxsize == 2147483647
+
+
+def get_platform():
+    # type: () -> str
+    """Return our platform name 'win32', 'linux_x86_64'"""
+    if sys.platform == 'darwin':
+        # distutils.util.get_platform() returns the release based on the value
+        # of MACOSX_DEPLOYMENT_TARGET on which Python was built, which may
+        # be significantly older than the user's current machine.
+        release, _, machine = platform.mac_ver()
+        split_ver = release.split('.')
+
+        if machine == "x86_64" and _is_running_32bit():
+            machine = "i386"
+        elif machine == "ppc64" and _is_running_32bit():
+            machine = "ppc"
+
+        return 'macosx_{}_{}_{}'.format(split_ver[0], split_ver[1], machine)
+
+    # XXX remove distutils dependency
+    result = distutils.util.get_platform().replace('.', '_').replace('-', '_')
+    if result == "linux_x86_64" and _is_running_32bit():
+        # 32 bit Python program (running on a 64 bit Linux): pip should only
+        # install and run 32 bit compiled extensions in that case.
+        result = "linux_i686"
+
+    return result
+
+
+def is_manylinux1_compatible():
+    # type: () -> bool
+    # Only Linux, and only x86-64 / i686
+    if get_platform() not in {"linux_x86_64", "linux_i686"}:
+        return False
+
+    # Check for presence of _manylinux module
+    try:
+        import _manylinux
+        return bool(_manylinux.manylinux1_compatible)
+    except (ImportError, AttributeError):
+        # Fall through to heuristic check below
+        pass
+
+    # Check glibc version. CentOS 5 uses glibc 2.5.
+    return pip._internal.utils.glibc.have_compatible_glibc(2, 5)
+
+
+def is_manylinux2010_compatible():
+    # type: () -> bool
+    # Only Linux, and only x86-64 / i686
+    if get_platform() not in {"linux_x86_64", "linux_i686"}:
+        return False
+
+    # Check for presence of _manylinux module
+    try:
+        import _manylinux
+        return bool(_manylinux.manylinux2010_compatible)
+    except (ImportError, AttributeError):
+        # Fall through to heuristic check below
+        pass
+
+    # Check glibc version. CentOS 6 uses glibc 2.12.
+    return pip._internal.utils.glibc.have_compatible_glibc(2, 12)
+
+
+def get_darwin_arches(major, minor, machine):
+    # type: (int, int, str) -> List[str]
+    """Return a list of supported arches (including group arches) for
+    the given major, minor and machine architecture of an macOS machine.
+    """
+    arches = []
+
+    def _supports_arch(major, minor, arch):
+        # type: (int, int, str) -> bool
+        # Looking at the application support for macOS versions in the chart
+        # provided by https://en.wikipedia.org/wiki/OS_X#Versions it appears
+        # our timeline looks roughly like:
+        #
+        # 10.0 - Introduces ppc support.
+        # 10.4 - Introduces ppc64, i386, and x86_64 support, however the ppc64
+        #        and x86_64 support is CLI only, and cannot be used for GUI
+        #        applications.
+        # 10.5 - Extends ppc64 and x86_64 support to cover GUI applications.
+        # 10.6 - Drops support for ppc64
+        # 10.7 - Drops support for ppc
+        #
+        # Given that we do not know if we're installing a CLI or a GUI
+        # application, we must be conservative and assume it might be a GUI
+        # application and behave as if ppc64 and x86_64 support did not occur
+        # until 10.5.
+        #
+        # Note: The above information is taken from the "Application support"
+        #       column in the chart not the "Processor support" since I believe
+        #       that we care about what instruction sets an application can use
+        #       not which processors the OS supports.
+        if arch == 'ppc':
+            return (major, minor) <= (10, 5)
+        if arch == 'ppc64':
+            return (major, minor) == (10, 5)
+        if arch == 'i386':
+            return (major, minor) >= (10, 4)
+        if arch == 'x86_64':
+            return (major, minor) >= (10, 5)
+        if arch in groups:
+            for garch in groups[arch]:
+                if _supports_arch(major, minor, garch):
+                    return True
+        return False
+
+    groups = OrderedDict([
+        ("fat", ("i386", "ppc")),
+        ("intel", ("x86_64", "i386")),
+        ("fat64", ("x86_64", "ppc64")),
+        ("fat32", ("x86_64", "i386", "ppc")),
+    ])  # type: Dict[str, Tuple[str, ...]]
+
+    if _supports_arch(major, minor, machine):
+        arches.append(machine)
+
+    for garch in groups:
+        if machine in groups[garch] and _supports_arch(major, minor, garch):
+            arches.append(garch)
+
+    arches.append('universal')
+
+    return arches
+
+
+def get_all_minor_versions_as_strings(version_info):
+    # type: (Tuple[int, ...]) -> List[str]
+    versions = []
+    major = version_info[:-1]
+    # Support all previous minor Python versions.
+    for minor in range(version_info[-1], -1, -1):
+        versions.append(''.join(map(str, major + (minor,))))
+    return versions
+
+
+def get_supported(
+    versions=None,  # type: Optional[List[str]]
+    noarch=False,  # type: bool
+    platform=None,  # type: Optional[str]
+    impl=None,  # type: Optional[str]
+    abi=None  # type: Optional[str]
+):
+    # type: (...) -> List[Pep425Tag]
+    """Return a list of supported tags for each version specified in
+    `versions`.
+
+    :param versions: a list of string versions, of the form ["33", "32"],
+        or None. The first version will be assumed to support our ABI.
+    :param platform: specify the exact platform you want valid
+        tags for, or None. If None, use the local system platform.
+    :param impl: specify the exact implementation you want valid
+        tags for, or None. If None, use the local interpreter impl.
+    :param abi: specify the exact abi you want valid
+        tags for, or None. If None, use the local interpreter abi.
+    """
+    supported = []
+
+    # Versions must be given with respect to the preference
+    if versions is None:
+        version_info = get_impl_version_info()
+        versions = get_all_minor_versions_as_strings(version_info)
+
+    impl = impl or get_abbr_impl()
+
+    abis = []  # type: List[str]
+
+    abi = abi or get_abi_tag()
+    if abi:
+        abis[0:0] = [abi]
+
+    abi3s = set()
+    for suffix in get_extension_suffixes():
+        if suffix.startswith('.abi'):
+            abi3s.add(suffix.split('.', 2)[1])
+
+    abis.extend(sorted(list(abi3s)))
+
+    abis.append('none')
+
+    if not noarch:
+        arch = platform or get_platform()
+        arch_prefix, arch_sep, arch_suffix = arch.partition('_')
+        if arch.startswith('macosx'):
+            # support macosx-10.6-intel on macosx-10.9-x86_64
+            match = _osx_arch_pat.match(arch)
+            if match:
+                name, major, minor, actual_arch = match.groups()
+                tpl = '{}_{}_%i_%s'.format(name, major)
+                arches = []
+                for m in reversed(range(int(minor) + 1)):
+                    for a in get_darwin_arches(int(major), m, actual_arch):
+                        arches.append(tpl % (m, a))
+            else:
+                # arch pattern didn't match (?!)
+                arches = [arch]
+        elif arch_prefix == 'manylinux2010':
+            # manylinux1 wheels run on most manylinux2010 systems with the
+            # exception of wheels depending on ncurses. PEP 571 states
+            # manylinux1 wheels should be considered manylinux2010 wheels:
+            # https://www.python.org/dev/peps/pep-0571/#backwards-compatibility-with-manylinux1-wheels
+            arches = [arch, 'manylinux1' + arch_sep + arch_suffix]
+        elif platform is None:
+            arches = []
+            if is_manylinux2010_compatible():
+                arches.append('manylinux2010' + arch_sep + arch_suffix)
+            if is_manylinux1_compatible():
+                arches.append('manylinux1' + arch_sep + arch_suffix)
+            arches.append(arch)
+        else:
+            arches = [arch]
+
+        # Current version, current API (built specifically for our Python):
+        for abi in abis:
+            for arch in arches:
+                supported.append(('%s%s' % (impl, versions[0]), abi, arch))
+
+        # abi3 modules compatible with older version of Python
+        for version in versions[1:]:
+            # abi3 was introduced in Python 3.2
+            if version in {'31', '30'}:
+                break
+            for abi in abi3s:   # empty set if not Python 3
+                for arch in arches:
+                    supported.append(("%s%s" % (impl, version), abi, arch))
+
+        # Has binaries, does not use the Python API:
+        for arch in arches:
+            supported.append(('py%s' % (versions[0][0]), 'none', arch))
+
+    # No abi / arch, but requires our implementation:
+    supported.append(('%s%s' % (impl, versions[0]), 'none', 'any'))
+    # Tagged specifically as being cross-version compatible
+    # (with just the major version specified)
+    supported.append(('%s%s' % (impl, versions[0][0]), 'none', 'any'))
+
+    # No abi / arch, generic Python
+    for i, version in enumerate(versions):
+        supported.append(('py%s' % (version,), 'none', 'any'))
+        if i == 0:
+            supported.append(('py%s' % (version[0]), 'none', 'any'))
+
+    return supported
+
+
+implementation_tag = get_impl_tag()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pyproject.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pyproject.py
new file mode 100644
index 0000000..8d739a6
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/pyproject.py
@@ -0,0 +1,171 @@
+from __future__ import absolute_import
+
+import io
+import os
+import sys
+
+from pip._vendor import pytoml, six
+
+from pip._internal.exceptions import InstallationError
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Tuple, Optional, List  # noqa: F401
+
+
+def _is_list_of_str(obj):
+    # type: (Any) -> bool
+    return (
+        isinstance(obj, list) and
+        all(isinstance(item, six.string_types) for item in obj)
+    )
+
+
+def make_pyproject_path(setup_py_dir):
+    # type: (str) -> str
+    path = os.path.join(setup_py_dir, 'pyproject.toml')
+
+    # Python2 __file__ should not be unicode
+    if six.PY2 and isinstance(path, six.text_type):
+        path = path.encode(sys.getfilesystemencoding())
+
+    return path
+
+
+def load_pyproject_toml(
+    use_pep517,  # type: Optional[bool]
+    pyproject_toml,  # type: str
+    setup_py,  # type: str
+    req_name  # type: str
+):
+    # type: (...) -> Optional[Tuple[List[str], str, List[str]]]
+    """Load the pyproject.toml file.
+
+    Parameters:
+        use_pep517 - Has the user requested PEP 517 processing? None
+                     means the user hasn't explicitly specified.
+        pyproject_toml - Location of the project's pyproject.toml file
+        setup_py - Location of the project's setup.py file
+        req_name - The name of the requirement we're processing (for
+                   error reporting)
+
+    Returns:
+        None if we should use the legacy code path, otherwise a tuple
+        (
+            requirements from pyproject.toml,
+            name of PEP 517 backend,
+            requirements we should check are installed after setting
+                up the build environment
+        )
+    """
+    has_pyproject = os.path.isfile(pyproject_toml)
+    has_setup = os.path.isfile(setup_py)
+
+    if has_pyproject:
+        with io.open(pyproject_toml, encoding="utf-8") as f:
+            pp_toml = pytoml.load(f)
+        build_system = pp_toml.get("build-system")
+    else:
+        build_system = None
+
+    # The following cases must use PEP 517
+    # We check for use_pep517 being non-None and falsey because that means
+    # the user explicitly requested --no-use-pep517.  The value 0 as
+    # opposed to False can occur when the value is provided via an
+    # environment variable or config file option (due to the quirk of
+    # strtobool() returning an integer in pip's configuration code).
+    if has_pyproject and not has_setup:
+        if use_pep517 is not None and not use_pep517:
+            raise InstallationError(
+                "Disabling PEP 517 processing is invalid: "
+                "project does not have a setup.py"
+            )
+        use_pep517 = True
+    elif build_system and "build-backend" in build_system:
+        if use_pep517 is not None and not use_pep517:
+            raise InstallationError(
+                "Disabling PEP 517 processing is invalid: "
+                "project specifies a build backend of {} "
+                "in pyproject.toml".format(
+                    build_system["build-backend"]
+                )
+            )
+        use_pep517 = True
+
+    # If we haven't worked out whether to use PEP 517 yet,
+    # and the user hasn't explicitly stated a preference,
+    # we do so if the project has a pyproject.toml file.
+    elif use_pep517 is None:
+        use_pep517 = has_pyproject
+
+    # At this point, we know whether we're going to use PEP 517.
+    assert use_pep517 is not None
+
+    # If we're using the legacy code path, there is nothing further
+    # for us to do here.
+    if not use_pep517:
+        return None
+
+    if build_system is None:
+        # Either the user has a pyproject.toml with no build-system
+        # section, or the user has no pyproject.toml, but has opted in
+        # explicitly via --use-pep517.
+        # In the absence of any explicit backend specification, we
+        # assume the setuptools backend that most closely emulates the
+        # traditional direct setup.py execution, and require wheel and
+        # a version of setuptools that supports that backend.
+
+        build_system = {
+            "requires": ["setuptools>=40.8.0", "wheel"],
+            "build-backend": "setuptools.build_meta:__legacy__",
+        }
+
+    # If we're using PEP 517, we have build system information (either
+    # from pyproject.toml, or defaulted by the code above).
+    # Note that at this point, we do not know if the user has actually
+    # specified a backend, though.
+    assert build_system is not None
+
+    # Ensure that the build-system section in pyproject.toml conforms
+    # to PEP 518.
+    error_template = (
+        "{package} has a pyproject.toml file that does not comply "
+        "with PEP 518: {reason}"
+    )
+
+    # Specifying the build-system table but not the requires key is invalid
+    if "requires" not in build_system:
+        raise InstallationError(
+            error_template.format(package=req_name, reason=(
+                "it has a 'build-system' table but not "
+                "'build-system.requires' which is mandatory in the table"
+            ))
+        )
+
+    # Error out if requires is not a list of strings
+    requires = build_system["requires"]
+    if not _is_list_of_str(requires):
+        raise InstallationError(error_template.format(
+            package=req_name,
+            reason="'build-system.requires' is not a list of strings.",
+        ))
+
+    backend = build_system.get("build-backend")
+    check = []  # type: List[str]
+    if backend is None:
+        # If the user didn't specify a backend, we assume they want to use
+        # the setuptools backend. But we can't be sure they have included
+        # a version of setuptools which supplies the backend, or wheel
+        # (which is needed by the backend) in their requirements. So we
+        # make a note to check that those requirements are present once
+        # we have set up the environment.
+        # This is quite a lot of work to check for a very specific case. But
+        # the problem is, that case is potentially quite common - projects that
+        # adopted PEP 518 early for the ability to specify requirements to
+        # execute setup.py, but never considered needing to mention the build
+        # tools themselves. The original PEP 518 code had a similar check (but
+        # implemented in a different way).
+        backend = "setuptools.build_meta:__legacy__"
+        check = ["setuptools>=40.8.0", "wheel"]
+
+    return (requires, backend, check)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/__init__.py
new file mode 100644
index 0000000..5e4eb92
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/__init__.py
@@ -0,0 +1,77 @@
+from __future__ import absolute_import
+
+import logging
+
+from .req_install import InstallRequirement
+from .req_set import RequirementSet
+from .req_file import parse_requirements
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import List, Sequence  # noqa: F401
+
+__all__ = [
+    "RequirementSet", "InstallRequirement",
+    "parse_requirements", "install_given_reqs",
+]
+
+logger = logging.getLogger(__name__)
+
+
+def install_given_reqs(
+    to_install,  # type: List[InstallRequirement]
+    install_options,  # type: List[str]
+    global_options=(),  # type: Sequence[str]
+    *args, **kwargs
+):
+    # type: (...) -> List[InstallRequirement]
+    """
+    Install everything in the given list.
+
+    (to be called after having downloaded and unpacked the packages)
+    """
+
+    if to_install:
+        logger.info(
+            'Installing collected packages: %s',
+            ', '.join([req.name for req in to_install]),
+        )
+
+    with indent_log():
+        for requirement in to_install:
+            if requirement.conflicts_with:
+                logger.info(
+                    'Found existing installation: %s',
+                    requirement.conflicts_with,
+                )
+                with indent_log():
+                    uninstalled_pathset = requirement.uninstall(
+                        auto_confirm=True
+                    )
+            try:
+                requirement.install(
+                    install_options,
+                    global_options,
+                    *args,
+                    **kwargs
+                )
+            except Exception:
+                should_rollback = (
+                    requirement.conflicts_with and
+                    not requirement.install_succeeded
+                )
+                # if install did not succeed, rollback previous uninstall
+                if should_rollback:
+                    uninstalled_pathset.rollback()
+                raise
+            else:
+                should_commit = (
+                    requirement.conflicts_with and
+                    requirement.install_succeeded
+                )
+                if should_commit:
+                    uninstalled_pathset.commit()
+            requirement.remove_temporary_source()
+
+    return to_install
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/constructors.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/constructors.py
new file mode 100644
index 0000000..1eed1dd
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/constructors.py
@@ -0,0 +1,339 @@
+"""Backing implementation for InstallRequirement's various constructors
+
+The idea here is that these formed a major chunk of InstallRequirement's size
+so, moving them and support code dedicated to them outside of that class
+helps creates for better understandability for the rest of the code.
+
+These are meant to be used elsewhere within pip to create instances of
+InstallRequirement.
+"""
+
+import logging
+import os
+import re
+
+from pip._vendor.packaging.markers import Marker
+from pip._vendor.packaging.requirements import InvalidRequirement, Requirement
+from pip._vendor.packaging.specifiers import Specifier
+from pip._vendor.pkg_resources import RequirementParseError, parse_requirements
+
+from pip._internal.download import (
+    is_archive_file, is_url, path_to_url, url_to_path,
+)
+from pip._internal.exceptions import InstallationError
+from pip._internal.models.index import PyPI, TestPyPI
+from pip._internal.models.link import Link
+from pip._internal.pyproject import make_pyproject_path
+from pip._internal.req.req_install import InstallRequirement
+from pip._internal.utils.misc import is_installable_dir
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.vcs import vcs
+from pip._internal.wheel import Wheel
+
+if MYPY_CHECK_RUNNING:
+    from typing import (   # noqa: F401
+        Optional, Tuple, Set, Any, Union, Text, Dict,
+    )
+    from pip._internal.cache import WheelCache  # noqa: F401
+
+
+__all__ = [
+    "install_req_from_editable", "install_req_from_line",
+    "parse_editable"
+]
+
+logger = logging.getLogger(__name__)
+operators = Specifier._operators.keys()
+
+
+def _strip_extras(path):
+    # type: (str) -> Tuple[str, Optional[str]]
+    m = re.match(r'^(.+)(\[[^\]]+\])$', path)
+    extras = None
+    if m:
+        path_no_extras = m.group(1)
+        extras = m.group(2)
+    else:
+        path_no_extras = path
+
+    return path_no_extras, extras
+
+
+def parse_editable(editable_req):
+    # type: (str) -> Tuple[Optional[str], str, Optional[Set[str]]]
+    """Parses an editable requirement into:
+        - a requirement name
+        - an URL
+        - extras
+        - editable options
+    Accepted requirements:
+        svn+http://blahblah@rev#egg=Foobar[baz]&subdirectory=version_subdir
+        .[some_extra]
+    """
+
+    url = editable_req
+
+    # If a file path is specified with extras, strip off the extras.
+    url_no_extras, extras = _strip_extras(url)
+
+    if os.path.isdir(url_no_extras):
+        if not os.path.exists(os.path.join(url_no_extras, 'setup.py')):
+            msg = (
+                'File "setup.py" not found. Directory cannot be installed '
+                'in editable mode: {}'.format(os.path.abspath(url_no_extras))
+            )
+            pyproject_path = make_pyproject_path(url_no_extras)
+            if os.path.isfile(pyproject_path):
+                msg += (
+                    '\n(A "pyproject.toml" file was found, but editable '
+                    'mode currently requires a setup.py based build.)'
+                )
+            raise InstallationError(msg)
+
+        # Treating it as code that has already been checked out
+        url_no_extras = path_to_url(url_no_extras)
+
+    if url_no_extras.lower().startswith('file:'):
+        package_name = Link(url_no_extras).egg_fragment
+        if extras:
+            return (
+                package_name,
+                url_no_extras,
+                Requirement("placeholder" + extras.lower()).extras,
+            )
+        else:
+            return package_name, url_no_extras, None
+
+    for version_control in vcs:
+        if url.lower().startswith('%s:' % version_control):
+            url = '%s+%s' % (version_control, url)
+            break
+
+    if '+' not in url:
+        raise InstallationError(
+            '%s should either be a path to a local project or a VCS url '
+            'beginning with svn+, git+, hg+, or bzr+' %
+            editable_req
+        )
+
+    vc_type = url.split('+', 1)[0].lower()
+
+    if not vcs.get_backend(vc_type):
+        error_message = 'For --editable=%s only ' % editable_req + \
+            ', '.join([backend.name + '+URL' for backend in vcs.backends]) + \
+            ' is currently supported'
+        raise InstallationError(error_message)
+
+    package_name = Link(url).egg_fragment
+    if not package_name:
+        raise InstallationError(
+            "Could not detect requirement name for '%s', please specify one "
+            "with #egg=your_package_name" % editable_req
+        )
+    return package_name, url, None
+
+
+def deduce_helpful_msg(req):
+    # type: (str) -> str
+    """Returns helpful msg in case requirements file does not exist,
+    or cannot be parsed.
+
+    :params req: Requirements file path
+    """
+    msg = ""
+    if os.path.exists(req):
+        msg = " It does exist."
+        # Try to parse and check if it is a requirements file.
+        try:
+            with open(req, 'r') as fp:
+                # parse first line only
+                next(parse_requirements(fp.read()))
+                msg += " The argument you provided " + \
+                    "(%s) appears to be a" % (req) + \
+                    " requirements file. If that is the" + \
+                    " case, use the '-r' flag to install" + \
+                    " the packages specified within it."
+        except RequirementParseError:
+            logger.debug("Cannot parse '%s' as requirements \
+            file" % (req), exc_info=True)
+    else:
+        msg += " File '%s' does not exist." % (req)
+    return msg
+
+
+# ---- The actual constructors follow ----
+
+
+def install_req_from_editable(
+    editable_req,  # type: str
+    comes_from=None,  # type: Optional[str]
+    use_pep517=None,  # type: Optional[bool]
+    isolated=False,  # type: bool
+    options=None,  # type: Optional[Dict[str, Any]]
+    wheel_cache=None,  # type: Optional[WheelCache]
+    constraint=False  # type: bool
+):
+    # type: (...) -> InstallRequirement
+    name, url, extras_override = parse_editable(editable_req)
+    if url.startswith('file:'):
+        source_dir = url_to_path(url)
+    else:
+        source_dir = None
+
+    if name is not None:
+        try:
+            req = Requirement(name)
+        except InvalidRequirement:
+            raise InstallationError("Invalid requirement: '%s'" % name)
+    else:
+        req = None
+    return InstallRequirement(
+        req, comes_from, source_dir=source_dir,
+        editable=True,
+        link=Link(url),
+        constraint=constraint,
+        use_pep517=use_pep517,
+        isolated=isolated,
+        options=options if options else {},
+        wheel_cache=wheel_cache,
+        extras=extras_override or (),
+    )
+
+
+def install_req_from_line(
+    name,  # type: str
+    comes_from=None,  # type: Optional[Union[str, InstallRequirement]]
+    use_pep517=None,  # type: Optional[bool]
+    isolated=False,  # type: bool
+    options=None,  # type: Optional[Dict[str, Any]]
+    wheel_cache=None,  # type: Optional[WheelCache]
+    constraint=False  # type: bool
+):
+    # type: (...) -> InstallRequirement
+    """Creates an InstallRequirement from a name, which might be a
+    requirement, directory containing 'setup.py', filename, or URL.
+    """
+    if is_url(name):
+        marker_sep = '; '
+    else:
+        marker_sep = ';'
+    if marker_sep in name:
+        name, markers_as_string = name.split(marker_sep, 1)
+        markers_as_string = markers_as_string.strip()
+        if not markers_as_string:
+            markers = None
+        else:
+            markers = Marker(markers_as_string)
+    else:
+        markers = None
+    name = name.strip()
+    req_as_string = None
+    path = os.path.normpath(os.path.abspath(name))
+    link = None
+    extras_as_string = None
+
+    if is_url(name):
+        link = Link(name)
+    else:
+        p, extras_as_string = _strip_extras(path)
+        looks_like_dir = os.path.isdir(p) and (
+            os.path.sep in name or
+            (os.path.altsep is not None and os.path.altsep in name) or
+            name.startswith('.')
+        )
+        if looks_like_dir:
+            if not is_installable_dir(p):
+                raise InstallationError(
+                    "Directory %r is not installable. Neither 'setup.py' "
+                    "nor 'pyproject.toml' found." % name
+                )
+            link = Link(path_to_url(p))
+        elif is_archive_file(p):
+            if not os.path.isfile(p):
+                logger.warning(
+                    'Requirement %r looks like a filename, but the '
+                    'file does not exist',
+                    name
+                )
+            link = Link(path_to_url(p))
+
+    # it's a local file, dir, or url
+    if link:
+        # Handle relative file URLs
+        if link.scheme == 'file' and re.search(r'\.\./', link.url):
+            link = Link(
+                path_to_url(os.path.normpath(os.path.abspath(link.path))))
+        # wheel file
+        if link.is_wheel:
+            wheel = Wheel(link.filename)  # can raise InvalidWheelFilename
+            req_as_string = "%s==%s" % (wheel.name, wheel.version)
+        else:
+            # set the req to the egg fragment.  when it's not there, this
+            # will become an 'unnamed' requirement
+            req_as_string = link.egg_fragment
+
+    # a requirement specifier
+    else:
+        req_as_string = name
+
+    if extras_as_string:
+        extras = Requirement("placeholder" + extras_as_string.lower()).extras
+    else:
+        extras = ()
+    if req_as_string is not None:
+        try:
+            req = Requirement(req_as_string)
+        except InvalidRequirement:
+            if os.path.sep in req_as_string:
+                add_msg = "It looks like a path."
+                add_msg += deduce_helpful_msg(req_as_string)
+            elif ('=' in req_as_string and
+                  not any(op in req_as_string for op in operators)):
+                add_msg = "= is not a valid operator. Did you mean == ?"
+            else:
+                add_msg = ""
+            raise InstallationError(
+                "Invalid requirement: '%s'\n%s" % (req_as_string, add_msg)
+            )
+    else:
+        req = None
+
+    return InstallRequirement(
+        req, comes_from, link=link, markers=markers,
+        use_pep517=use_pep517, isolated=isolated,
+        options=options if options else {},
+        wheel_cache=wheel_cache,
+        constraint=constraint,
+        extras=extras,
+    )
+
+
+def install_req_from_req_string(
+    req_string,  # type: str
+    comes_from=None,  # type: Optional[InstallRequirement]
+    isolated=False,  # type: bool
+    wheel_cache=None,  # type: Optional[WheelCache]
+    use_pep517=None  # type: Optional[bool]
+):
+    # type: (...) -> InstallRequirement
+    try:
+        req = Requirement(req_string)
+    except InvalidRequirement:
+        raise InstallationError("Invalid requirement: '%s'" % req)
+
+    domains_not_allowed = [
+        PyPI.file_storage_domain,
+        TestPyPI.file_storage_domain,
+    ]
+    if req.url and comes_from.link.netloc in domains_not_allowed:
+        # Explicitly disallow pypi packages that depend on external urls
+        raise InstallationError(
+            "Packages installed from PyPI cannot depend on packages "
+            "which are not also hosted on PyPI.\n"
+            "%s depends on %s " % (comes_from.name, req)
+        )
+
+    return InstallRequirement(
+        req, comes_from, isolated=isolated, wheel_cache=wheel_cache,
+        use_pep517=use_pep517
+    )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_file.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_file.py
new file mode 100644
index 0000000..726f2f6
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_file.py
@@ -0,0 +1,382 @@
+"""
+Requirements file parsing
+"""
+
+from __future__ import absolute_import
+
+import optparse
+import os
+import re
+import shlex
+import sys
+
+from pip._vendor.six.moves import filterfalse
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+from pip._internal.cli import cmdoptions
+from pip._internal.download import get_file_content
+from pip._internal.exceptions import RequirementsFileParseError
+from pip._internal.req.constructors import (
+    install_req_from_editable, install_req_from_line,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Iterator, Tuple, Optional, List, Callable, Text
+    )
+    from pip._internal.req import InstallRequirement  # noqa: F401
+    from pip._internal.cache import WheelCache  # noqa: F401
+    from pip._internal.index import PackageFinder  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+
+    ReqFileLines = Iterator[Tuple[int, Text]]
+
+__all__ = ['parse_requirements']
+
+SCHEME_RE = re.compile(r'^(http|https|file):', re.I)
+COMMENT_RE = re.compile(r'(^|\s)+#.*$')
+
+# Matches environment variable-style values in '${MY_VARIABLE_1}' with the
+# variable name consisting of only uppercase letters, digits or the '_'
+# (underscore). This follows the POSIX standard defined in IEEE Std 1003.1,
+# 2013 Edition.
+ENV_VAR_RE = re.compile(r'(?P<var>\$\{(?P<name>[A-Z0-9_]+)\})')
+
+SUPPORTED_OPTIONS = [
+    cmdoptions.constraints,
+    cmdoptions.editable,
+    cmdoptions.requirements,
+    cmdoptions.no_index,
+    cmdoptions.index_url,
+    cmdoptions.find_links,
+    cmdoptions.extra_index_url,
+    cmdoptions.always_unzip,
+    cmdoptions.no_binary,
+    cmdoptions.only_binary,
+    cmdoptions.pre,
+    cmdoptions.trusted_host,
+    cmdoptions.require_hashes,
+]  # type: List[Callable[..., optparse.Option]]
+
+# options to be passed to requirements
+SUPPORTED_OPTIONS_REQ = [
+    cmdoptions.install_options,
+    cmdoptions.global_options,
+    cmdoptions.hash,
+]  # type: List[Callable[..., optparse.Option]]
+
+# the 'dest' string values
+SUPPORTED_OPTIONS_REQ_DEST = [str(o().dest) for o in SUPPORTED_OPTIONS_REQ]
+
+
+def parse_requirements(
+    filename,  # type: str
+    finder=None,  # type: Optional[PackageFinder]
+    comes_from=None,  # type: Optional[str]
+    options=None,  # type: Optional[optparse.Values]
+    session=None,  # type: Optional[PipSession]
+    constraint=False,  # type: bool
+    wheel_cache=None,  # type: Optional[WheelCache]
+    use_pep517=None  # type: Optional[bool]
+):
+    # type: (...) -> Iterator[InstallRequirement]
+    """Parse a requirements file and yield InstallRequirement instances.
+
+    :param filename:    Path or url of requirements file.
+    :param finder:      Instance of pip.index.PackageFinder.
+    :param comes_from:  Origin description of requirements.
+    :param options:     cli options.
+    :param session:     Instance of pip.download.PipSession.
+    :param constraint:  If true, parsing a constraint file rather than
+        requirements file.
+    :param wheel_cache: Instance of pip.wheel.WheelCache
+    :param use_pep517:  Value of the --use-pep517 option.
+    """
+    if session is None:
+        raise TypeError(
+            "parse_requirements() missing 1 required keyword argument: "
+            "'session'"
+        )
+
+    _, content = get_file_content(
+        filename, comes_from=comes_from, session=session
+    )
+
+    lines_enum = preprocess(content, options)
+
+    for line_number, line in lines_enum:
+        req_iter = process_line(line, filename, line_number, finder,
+                                comes_from, options, session, wheel_cache,
+                                use_pep517=use_pep517, constraint=constraint)
+        for req in req_iter:
+            yield req
+
+
+def preprocess(content, options):
+    # type: (Text, Optional[optparse.Values]) -> ReqFileLines
+    """Split, filter, and join lines, and return a line iterator
+
+    :param content: the content of the requirements file
+    :param options: cli options
+    """
+    lines_enum = enumerate(content.splitlines(), start=1)  # type: ReqFileLines
+    lines_enum = join_lines(lines_enum)
+    lines_enum = ignore_comments(lines_enum)
+    lines_enum = skip_regex(lines_enum, options)
+    lines_enum = expand_env_variables(lines_enum)
+    return lines_enum
+
+
+def process_line(
+    line,  # type: Text
+    filename,  # type: str
+    line_number,  # type: int
+    finder=None,  # type: Optional[PackageFinder]
+    comes_from=None,  # type: Optional[str]
+    options=None,  # type: Optional[optparse.Values]
+    session=None,  # type: Optional[PipSession]
+    wheel_cache=None,  # type: Optional[WheelCache]
+    use_pep517=None,  # type: Optional[bool]
+    constraint=False  # type: bool
+):
+    # type: (...) -> Iterator[InstallRequirement]
+    """Process a single requirements line; This can result in creating/yielding
+    requirements, or updating the finder.
+
+    For lines that contain requirements, the only options that have an effect
+    are from SUPPORTED_OPTIONS_REQ, and they are scoped to the
+    requirement. Other options from SUPPORTED_OPTIONS may be present, but are
+    ignored.
+
+    For lines that do not contain requirements, the only options that have an
+    effect are from SUPPORTED_OPTIONS. Options from SUPPORTED_OPTIONS_REQ may
+    be present, but are ignored. These lines may contain multiple options
+    (although our docs imply only one is supported), and all our parsed and
+    affect the finder.
+
+    :param constraint: If True, parsing a constraints file.
+    :param options: OptionParser options that we may update
+    """
+    parser = build_parser(line)
+    defaults = parser.get_default_values()
+    defaults.index_url = None
+    if finder:
+        defaults.format_control = finder.format_control
+    args_str, options_str = break_args_options(line)
+    # Prior to 2.7.3, shlex cannot deal with unicode entries
+    if sys.version_info < (2, 7, 3):
+        # https://github.com/python/mypy/issues/1174
+        options_str = options_str.encode('utf8')  # type: ignore
+    # https://github.com/python/mypy/issues/1174
+    opts, _ = parser.parse_args(
+        shlex.split(options_str), defaults)  # type: ignore
+
+    # preserve for the nested code path
+    line_comes_from = '%s %s (line %s)' % (
+        '-c' if constraint else '-r', filename, line_number,
+    )
+
+    # yield a line requirement
+    if args_str:
+        isolated = options.isolated_mode if options else False
+        if options:
+            cmdoptions.check_install_build_global(options, opts)
+        # get the options that apply to requirements
+        req_options = {}
+        for dest in SUPPORTED_OPTIONS_REQ_DEST:
+            if dest in opts.__dict__ and opts.__dict__[dest]:
+                req_options[dest] = opts.__dict__[dest]
+        yield install_req_from_line(
+            args_str, line_comes_from, constraint=constraint,
+            use_pep517=use_pep517,
+            isolated=isolated, options=req_options, wheel_cache=wheel_cache
+        )
+
+    # yield an editable requirement
+    elif opts.editables:
+        isolated = options.isolated_mode if options else False
+        yield install_req_from_editable(
+            opts.editables[0], comes_from=line_comes_from,
+            use_pep517=use_pep517,
+            constraint=constraint, isolated=isolated, wheel_cache=wheel_cache
+        )
+
+    # parse a nested requirements file
+    elif opts.requirements or opts.constraints:
+        if opts.requirements:
+            req_path = opts.requirements[0]
+            nested_constraint = False
+        else:
+            req_path = opts.constraints[0]
+            nested_constraint = True
+        # original file is over http
+        if SCHEME_RE.search(filename):
+            # do a url join so relative paths work
+            req_path = urllib_parse.urljoin(filename, req_path)
+        # original file and nested file are paths
+        elif not SCHEME_RE.search(req_path):
+            # do a join so relative paths work
+            req_path = os.path.join(os.path.dirname(filename), req_path)
+        # TODO: Why not use `comes_from='-r {} (line {})'` here as well?
+        parsed_reqs = parse_requirements(
+            req_path, finder, comes_from, options, session,
+            constraint=nested_constraint, wheel_cache=wheel_cache
+        )
+        for req in parsed_reqs:
+            yield req
+
+    # percolate hash-checking option upward
+    elif opts.require_hashes:
+        options.require_hashes = opts.require_hashes
+
+    # set finder options
+    elif finder:
+        if opts.index_url:
+            finder.index_urls = [opts.index_url]
+        if opts.no_index is True:
+            finder.index_urls = []
+        if opts.extra_index_urls:
+            finder.index_urls.extend(opts.extra_index_urls)
+        if opts.find_links:
+            # FIXME: it would be nice to keep track of the source
+            # of the find_links: support a find-links local path
+            # relative to a requirements file.
+            value = opts.find_links[0]
+            req_dir = os.path.dirname(os.path.abspath(filename))
+            relative_to_reqs_file = os.path.join(req_dir, value)
+            if os.path.exists(relative_to_reqs_file):
+                value = relative_to_reqs_file
+            finder.find_links.append(value)
+        if opts.pre:
+            finder.allow_all_prereleases = True
+        if opts.trusted_hosts:
+            finder.secure_origins.extend(
+                ("*", host, "*") for host in opts.trusted_hosts)
+
+
+def break_args_options(line):
+    # type: (Text) -> Tuple[str, Text]
+    """Break up the line into an args and options string.  We only want to shlex
+    (and then optparse) the options, not the args.  args can contain markers
+    which are corrupted by shlex.
+    """
+    tokens = line.split(' ')
+    args = []
+    options = tokens[:]
+    for token in tokens:
+        if token.startswith('-') or token.startswith('--'):
+            break
+        else:
+            args.append(token)
+            options.pop(0)
+    return ' '.join(args), ' '.join(options)  # type: ignore
+
+
+def build_parser(line):
+    # type: (Text) -> optparse.OptionParser
+    """
+    Return a parser for parsing requirement lines
+    """
+    parser = optparse.OptionParser(add_help_option=False)
+
+    option_factories = SUPPORTED_OPTIONS + SUPPORTED_OPTIONS_REQ
+    for option_factory in option_factories:
+        option = option_factory()
+        parser.add_option(option)
+
+    # By default optparse sys.exits on parsing errors. We want to wrap
+    # that in our own exception.
+    def parser_exit(self, msg):
+        # add offending line
+        msg = 'Invalid requirement: %s\n%s' % (line, msg)
+        raise RequirementsFileParseError(msg)
+    # NOTE: mypy disallows assigning to a method
+    #       https://github.com/python/mypy/issues/2427
+    parser.exit = parser_exit  # type: ignore
+
+    return parser
+
+
+def join_lines(lines_enum):
+    # type: (ReqFileLines) -> ReqFileLines
+    """Joins a line ending in '\' with the previous line (except when following
+    comments).  The joined line takes on the index of the first line.
+    """
+    primary_line_number = None
+    new_line = []  # type: List[Text]
+    for line_number, line in lines_enum:
+        if not line.endswith('\\') or COMMENT_RE.match(line):
+            if COMMENT_RE.match(line):
+                # this ensures comments are always matched later
+                line = ' ' + line
+            if new_line:
+                new_line.append(line)
+                yield primary_line_number, ''.join(new_line)
+                new_line = []
+            else:
+                yield line_number, line
+        else:
+            if not new_line:
+                primary_line_number = line_number
+            new_line.append(line.strip('\\'))
+
+    # last line contains \
+    if new_line:
+        yield primary_line_number, ''.join(new_line)
+
+    # TODO: handle space after '\'.
+
+
+def ignore_comments(lines_enum):
+    # type: (ReqFileLines) -> ReqFileLines
+    """
+    Strips comments and filter empty lines.
+    """
+    for line_number, line in lines_enum:
+        line = COMMENT_RE.sub('', line)
+        line = line.strip()
+        if line:
+            yield line_number, line
+
+
+def skip_regex(lines_enum, options):
+    # type: (ReqFileLines, Optional[optparse.Values]) -> ReqFileLines
+    """
+    Skip lines that match '--skip-requirements-regex' pattern
+
+    Note: the regex pattern is only built once
+    """
+    skip_regex = options.skip_requirements_regex if options else None
+    if skip_regex:
+        pattern = re.compile(skip_regex)
+        lines_enum = filterfalse(lambda e: pattern.search(e[1]), lines_enum)
+    return lines_enum
+
+
+def expand_env_variables(lines_enum):
+    # type: (ReqFileLines) -> ReqFileLines
+    """Replace all environment variables that can be retrieved via `os.getenv`.
+
+    The only allowed format for environment variables defined in the
+    requirement file is `${MY_VARIABLE_1}` to ensure two things:
+
+    1. Strings that contain a `$` aren't accidentally (partially) expanded.
+    2. Ensure consistency across platforms for requirement files.
+
+    These points are the result of a discusssion on the `github pull
+    request #3514 <https://github.com/pypa/pip/pull/3514>`_.
+
+    Valid characters in variable names follow the `POSIX standard
+    <http://pubs.opengroup.org/onlinepubs/9699919799/>`_ and are limited
+    to uppercase letter, digits and the `_` (underscore).
+    """
+    for line_number, line in lines_enum:
+        for env_var, var_name in ENV_VAR_RE.findall(line):
+            value = os.getenv(var_name)
+            if not value:
+                continue
+
+            line = line.replace(env_var, value)
+
+        yield line_number, line
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_install.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_install.py
new file mode 100644
index 0000000..a4834b0
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_install.py
@@ -0,0 +1,1021 @@
+from __future__ import absolute_import
+
+import logging
+import os
+import shutil
+import sys
+import sysconfig
+import zipfile
+from distutils.util import change_root
+
+from pip._vendor import pkg_resources, six
+from pip._vendor.packaging.requirements import Requirement
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.packaging.version import Version
+from pip._vendor.packaging.version import parse as parse_version
+from pip._vendor.pep517.wrappers import Pep517HookCaller
+
+from pip._internal import wheel
+from pip._internal.build_env import NoOpBuildEnvironment
+from pip._internal.exceptions import InstallationError
+from pip._internal.locations import (
+    PIP_DELETE_MARKER_FILENAME, running_under_virtualenv,
+)
+from pip._internal.models.link import Link
+from pip._internal.pyproject import load_pyproject_toml, make_pyproject_path
+from pip._internal.req.req_uninstall import UninstallPathSet
+from pip._internal.utils.compat import native_str
+from pip._internal.utils.hashes import Hashes
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    _make_build_dir, ask_path_exists, backup_dir, call_subprocess,
+    display_path, dist_in_site_packages, dist_in_usersite, ensure_dir,
+    get_installed_version, redact_password_from_url, rmtree,
+)
+from pip._internal.utils.packaging import get_metadata
+from pip._internal.utils.setuptools_build import SETUPTOOLS_SHIM
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import open_spinner
+from pip._internal.vcs import vcs
+from pip._internal.wheel import move_wheel_files
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Optional, Iterable, List, Union, Any, Text, Sequence, Dict
+    )
+    from pip._internal.build_env import BuildEnvironment  # noqa: F401
+    from pip._internal.cache import WheelCache  # noqa: F401
+    from pip._internal.index import PackageFinder  # noqa: F401
+    from pip._vendor.pkg_resources import Distribution  # noqa: F401
+    from pip._vendor.packaging.specifiers import SpecifierSet  # noqa: F401
+    from pip._vendor.packaging.markers import Marker  # noqa: F401
+
+
+logger = logging.getLogger(__name__)
+
+
+class InstallRequirement(object):
+    """
+    Represents something that may be installed later on, may have information
+    about where to fetch the relavant requirement and also contains logic for
+    installing the said requirement.
+    """
+
+    def __init__(
+        self,
+        req,  # type: Optional[Requirement]
+        comes_from,  # type: Optional[Union[str, InstallRequirement]]
+        source_dir=None,  # type: Optional[str]
+        editable=False,  # type: bool
+        link=None,  # type: Optional[Link]
+        update=True,  # type: bool
+        markers=None,  # type: Optional[Marker]
+        use_pep517=None,  # type: Optional[bool]
+        isolated=False,  # type: bool
+        options=None,  # type: Optional[Dict[str, Any]]
+        wheel_cache=None,  # type: Optional[WheelCache]
+        constraint=False,  # type: bool
+        extras=()  # type: Iterable[str]
+    ):
+        # type: (...) -> None
+        assert req is None or isinstance(req, Requirement), req
+        self.req = req
+        self.comes_from = comes_from
+        self.constraint = constraint
+        if source_dir is not None:
+            self.source_dir = os.path.normpath(os.path.abspath(source_dir))
+        else:
+            self.source_dir = None
+        self.editable = editable
+
+        self._wheel_cache = wheel_cache
+        if link is None and req and req.url:
+            # PEP 508 URL requirement
+            link = Link(req.url)
+        self.link = self.original_link = link
+
+        if extras:
+            self.extras = extras
+        elif req:
+            self.extras = {
+                pkg_resources.safe_extra(extra) for extra in req.extras
+            }
+        else:
+            self.extras = set()
+        if markers is None and req:
+            markers = req.marker
+        self.markers = markers
+
+        self._egg_info_path = None  # type: Optional[str]
+        # This holds the pkg_resources.Distribution object if this requirement
+        # is already available:
+        self.satisfied_by = None
+        # This hold the pkg_resources.Distribution object if this requirement
+        # conflicts with another installed distribution:
+        self.conflicts_with = None
+        # Temporary build location
+        self._temp_build_dir = TempDirectory(kind="req-build")
+        # Used to store the global directory where the _temp_build_dir should
+        # have been created. Cf _correct_build_location method.
+        self._ideal_build_dir = None  # type: Optional[str]
+        # True if the editable should be updated:
+        self.update = update
+        # Set to True after successful installation
+        self.install_succeeded = None  # type: Optional[bool]
+        # UninstallPathSet of uninstalled distribution (for possible rollback)
+        self.uninstalled_pathset = None
+        self.options = options if options else {}
+        # Set to True after successful preparation of this requirement
+        self.prepared = False
+        self.is_direct = False
+
+        self.isolated = isolated
+        self.build_env = NoOpBuildEnvironment()  # type: BuildEnvironment
+
+        # For PEP 517, the directory where we request the project metadata
+        # gets stored. We need this to pass to build_wheel, so the backend
+        # can ensure that the wheel matches the metadata (see the PEP for
+        # details).
+        self.metadata_directory = None  # type: Optional[str]
+
+        # The static build requirements (from pyproject.toml)
+        self.pyproject_requires = None  # type: Optional[List[str]]
+
+        # Build requirements that we will check are available
+        self.requirements_to_check = []  # type: List[str]
+
+        # The PEP 517 backend we should use to build the project
+        self.pep517_backend = None  # type: Optional[Pep517HookCaller]
+
+        # Are we using PEP 517 for this requirement?
+        # After pyproject.toml has been loaded, the only valid values are True
+        # and False. Before loading, None is valid (meaning "use the default").
+        # Setting an explicit value before loading pyproject.toml is supported,
+        # but after loading this flag should be treated as read only.
+        self.use_pep517 = use_pep517
+
+    def __str__(self):
+        if self.req:
+            s = str(self.req)
+            if self.link:
+                s += ' from %s' % redact_password_from_url(self.link.url)
+        elif self.link:
+            s = redact_password_from_url(self.link.url)
+        else:
+            s = '<InstallRequirement>'
+        if self.satisfied_by is not None:
+            s += ' in %s' % display_path(self.satisfied_by.location)
+        if self.comes_from:
+            if isinstance(self.comes_from, six.string_types):
+                comes_from = self.comes_from
+            else:
+                comes_from = self.comes_from.from_path()
+            if comes_from:
+                s += ' (from %s)' % comes_from
+        return s
+
+    def __repr__(self):
+        return '<%s object: %s editable=%r>' % (
+            self.__class__.__name__, str(self), self.editable)
+
+    def populate_link(self, finder, upgrade, require_hashes):
+        # type: (PackageFinder, bool, bool) -> None
+        """Ensure that if a link can be found for this, that it is found.
+
+        Note that self.link may still be None - if Upgrade is False and the
+        requirement is already installed.
+
+        If require_hashes is True, don't use the wheel cache, because cached
+        wheels, always built locally, have different hashes than the files
+        downloaded from the index server and thus throw false hash mismatches.
+        Furthermore, cached wheels at present have undeterministic contents due
+        to file modification times.
+        """
+        if self.link is None:
+            self.link = finder.find_requirement(self, upgrade)
+        if self._wheel_cache is not None and not require_hashes:
+            old_link = self.link
+            self.link = self._wheel_cache.get(self.link, self.name)
+            if old_link != self.link:
+                logger.debug('Using cached wheel link: %s', self.link)
+
+    # Things that are valid for all kinds of requirements?
+    @property
+    def name(self):
+        # type: () -> Optional[str]
+        if self.req is None:
+            return None
+        return native_str(pkg_resources.safe_name(self.req.name))
+
+    @property
+    def specifier(self):
+        # type: () -> SpecifierSet
+        return self.req.specifier
+
+    @property
+    def is_pinned(self):
+        # type: () -> bool
+        """Return whether I am pinned to an exact version.
+
+        For example, some-package==1.2 is pinned; some-package>1.2 is not.
+        """
+        specifiers = self.specifier
+        return (len(specifiers) == 1 and
+                next(iter(specifiers)).operator in {'==', '==='})
+
+    @property
+    def installed_version(self):
+        return get_installed_version(self.name)
+
+    def match_markers(self, extras_requested=None):
+        # type: (Optional[Iterable[str]]) -> bool
+        if not extras_requested:
+            # Provide an extra to safely evaluate the markers
+            # without matching any extra
+            extras_requested = ('',)
+        if self.markers is not None:
+            return any(
+                self.markers.evaluate({'extra': extra})
+                for extra in extras_requested)
+        else:
+            return True
+
+    @property
+    def has_hash_options(self):
+        # type: () -> bool
+        """Return whether any known-good hashes are specified as options.
+
+        These activate --require-hashes mode; hashes specified as part of a
+        URL do not.
+
+        """
+        return bool(self.options.get('hashes', {}))
+
+    def hashes(self, trust_internet=True):
+        # type: (bool) -> Hashes
+        """Return a hash-comparer that considers my option- and URL-based
+        hashes to be known-good.
+
+        Hashes in URLs--ones embedded in the requirements file, not ones
+        downloaded from an index server--are almost peers with ones from
+        flags. They satisfy --require-hashes (whether it was implicitly or
+        explicitly activated) but do not activate it. md5 and sha224 are not
+        allowed in flags, which should nudge people toward good algos. We
+        always OR all hashes together, even ones from URLs.
+
+        :param trust_internet: Whether to trust URL-based (#md5=...) hashes
+            downloaded from the internet, as by populate_link()
+
+        """
+        good_hashes = self.options.get('hashes', {}).copy()
+        link = self.link if trust_internet else self.original_link
+        if link and link.hash:
+            good_hashes.setdefault(link.hash_name, []).append(link.hash)
+        return Hashes(good_hashes)
+
+    def from_path(self):
+        # type: () -> Optional[str]
+        """Format a nice indicator to show where this "comes from"
+        """
+        if self.req is None:
+            return None
+        s = str(self.req)
+        if self.comes_from:
+            if isinstance(self.comes_from, six.string_types):
+                comes_from = self.comes_from
+            else:
+                comes_from = self.comes_from.from_path()
+            if comes_from:
+                s += '->' + comes_from
+        return s
+
+    def build_location(self, build_dir):
+        # type: (str) -> Optional[str]
+        assert build_dir is not None
+        if self._temp_build_dir.path is not None:
+            return self._temp_build_dir.path
+        if self.req is None:
+            # for requirement via a path to a directory: the name of the
+            # package is not available yet so we create a temp directory
+            # Once run_egg_info will have run, we'll be able
+            # to fix it via _correct_build_location
+            # Some systems have /tmp as a symlink which confuses custom
+            # builds (such as numpy). Thus, we ensure that the real path
+            # is returned.
+            self._temp_build_dir.create()
+            self._ideal_build_dir = build_dir
+
+            return self._temp_build_dir.path
+        if self.editable:
+            name = self.name.lower()
+        else:
+            name = self.name
+        # FIXME: Is there a better place to create the build_dir? (hg and bzr
+        # need this)
+        if not os.path.exists(build_dir):
+            logger.debug('Creating directory %s', build_dir)
+            _make_build_dir(build_dir)
+        return os.path.join(build_dir, name)
+
+    def _correct_build_location(self):
+        # type: () -> None
+        """Move self._temp_build_dir to self._ideal_build_dir/self.req.name
+
+        For some requirements (e.g. a path to a directory), the name of the
+        package is not available until we run egg_info, so the build_location
+        will return a temporary directory and store the _ideal_build_dir.
+
+        This is only called by self.run_egg_info to fix the temporary build
+        directory.
+        """
+        if self.source_dir is not None:
+            return
+        assert self.req is not None
+        assert self._temp_build_dir.path
+        assert (self._ideal_build_dir is not None and
+                self._ideal_build_dir.path)  # type: ignore
+        old_location = self._temp_build_dir.path
+        self._temp_build_dir.path = None
+
+        new_location = self.build_location(self._ideal_build_dir)
+        if os.path.exists(new_location):
+            raise InstallationError(
+                'A package already exists in %s; please remove it to continue'
+                % display_path(new_location))
+        logger.debug(
+            'Moving package %s from %s to new location %s',
+            self, display_path(old_location), display_path(new_location),
+        )
+        shutil.move(old_location, new_location)
+        self._temp_build_dir.path = new_location
+        self._ideal_build_dir = None
+        self.source_dir = os.path.normpath(os.path.abspath(new_location))
+        self._egg_info_path = None
+
+        # Correct the metadata directory, if it exists
+        if self.metadata_directory:
+            old_meta = self.metadata_directory
+            rel = os.path.relpath(old_meta, start=old_location)
+            new_meta = os.path.join(new_location, rel)
+            new_meta = os.path.normpath(os.path.abspath(new_meta))
+            self.metadata_directory = new_meta
+
+    def remove_temporary_source(self):
+        # type: () -> None
+        """Remove the source files from this requirement, if they are marked
+        for deletion"""
+        if self.source_dir and os.path.exists(
+                os.path.join(self.source_dir, PIP_DELETE_MARKER_FILENAME)):
+            logger.debug('Removing source in %s', self.source_dir)
+            rmtree(self.source_dir)
+        self.source_dir = None
+        self._temp_build_dir.cleanup()
+        self.build_env.cleanup()
+
+    def check_if_exists(self, use_user_site):
+        # type: (bool) -> bool
+        """Find an installed distribution that satisfies or conflicts
+        with this requirement, and set self.satisfied_by or
+        self.conflicts_with appropriately.
+        """
+        if self.req is None:
+            return False
+        try:
+            # get_distribution() will resolve the entire list of requirements
+            # anyway, and we've already determined that we need the requirement
+            # in question, so strip the marker so that we don't try to
+            # evaluate it.
+            no_marker = Requirement(str(self.req))
+            no_marker.marker = None
+            self.satisfied_by = pkg_resources.get_distribution(str(no_marker))
+            if self.editable and self.satisfied_by:
+                self.conflicts_with = self.satisfied_by
+                # when installing editables, nothing pre-existing should ever
+                # satisfy
+                self.satisfied_by = None
+                return True
+        except pkg_resources.DistributionNotFound:
+            return False
+        except pkg_resources.VersionConflict:
+            existing_dist = pkg_resources.get_distribution(
+                self.req.name
+            )
+            if use_user_site:
+                if dist_in_usersite(existing_dist):
+                    self.conflicts_with = existing_dist
+                elif (running_under_virtualenv() and
+                        dist_in_site_packages(existing_dist)):
+                    raise InstallationError(
+                        "Will not install to the user site because it will "
+                        "lack sys.path precedence to %s in %s" %
+                        (existing_dist.project_name, existing_dist.location)
+                    )
+            else:
+                self.conflicts_with = existing_dist
+        return True
+
+    # Things valid for wheels
+    @property
+    def is_wheel(self):
+        # type: () -> bool
+        if not self.link:
+            return False
+        return self.link.is_wheel
+
+    def move_wheel_files(
+        self,
+        wheeldir,  # type: str
+        root=None,  # type: Optional[str]
+        home=None,  # type: Optional[str]
+        prefix=None,  # type: Optional[str]
+        warn_script_location=True,  # type: bool
+        use_user_site=False,  # type: bool
+        pycompile=True  # type: bool
+    ):
+        # type: (...) -> None
+        move_wheel_files(
+            self.name, self.req, wheeldir,
+            user=use_user_site,
+            home=home,
+            root=root,
+            prefix=prefix,
+            pycompile=pycompile,
+            isolated=self.isolated,
+            warn_script_location=warn_script_location,
+        )
+
+    # Things valid for sdists
+    @property
+    def setup_py_dir(self):
+        # type: () -> str
+        return os.path.join(
+            self.source_dir,
+            self.link and self.link.subdirectory_fragment or '')
+
+    @property
+    def setup_py(self):
+        # type: () -> str
+        assert self.source_dir, "No source dir for %s" % self
+
+        setup_py = os.path.join(self.setup_py_dir, 'setup.py')
+
+        # Python2 __file__ should not be unicode
+        if six.PY2 and isinstance(setup_py, six.text_type):
+            setup_py = setup_py.encode(sys.getfilesystemencoding())
+
+        return setup_py
+
+    @property
+    def pyproject_toml(self):
+        # type: () -> str
+        assert self.source_dir, "No source dir for %s" % self
+
+        return make_pyproject_path(self.setup_py_dir)
+
+    def load_pyproject_toml(self):
+        # type: () -> None
+        """Load the pyproject.toml file.
+
+        After calling this routine, all of the attributes related to PEP 517
+        processing for this requirement have been set. In particular, the
+        use_pep517 attribute can be used to determine whether we should
+        follow the PEP 517 or legacy (setup.py) code path.
+        """
+        pep517_data = load_pyproject_toml(
+            self.use_pep517,
+            self.pyproject_toml,
+            self.setup_py,
+            str(self)
+        )
+
+        if pep517_data is None:
+            self.use_pep517 = False
+        else:
+            self.use_pep517 = True
+            requires, backend, check = pep517_data
+            self.requirements_to_check = check
+            self.pyproject_requires = requires
+            self.pep517_backend = Pep517HookCaller(self.setup_py_dir, backend)
+
+            # Use a custom function to call subprocesses
+            self.spin_message = ""
+
+            def runner(cmd, cwd=None, extra_environ=None):
+                with open_spinner(self.spin_message) as spinner:
+                    call_subprocess(
+                        cmd,
+                        cwd=cwd,
+                        extra_environ=extra_environ,
+                        show_stdout=False,
+                        spinner=spinner
+                    )
+                self.spin_message = ""
+
+            self.pep517_backend._subprocess_runner = runner
+
+    def prepare_metadata(self):
+        # type: () -> None
+        """Ensure that project metadata is available.
+
+        Under PEP 517, call the backend hook to prepare the metadata.
+        Under legacy processing, call setup.py egg-info.
+        """
+        assert self.source_dir
+
+        with indent_log():
+            if self.use_pep517:
+                self.prepare_pep517_metadata()
+            else:
+                self.run_egg_info()
+
+        if not self.req:
+            if isinstance(parse_version(self.metadata["Version"]), Version):
+                op = "=="
+            else:
+                op = "==="
+            self.req = Requirement(
+                "".join([
+                    self.metadata["Name"],
+                    op,
+                    self.metadata["Version"],
+                ])
+            )
+            self._correct_build_location()
+        else:
+            metadata_name = canonicalize_name(self.metadata["Name"])
+            if canonicalize_name(self.req.name) != metadata_name:
+                logger.warning(
+                    'Generating metadata for package %s '
+                    'produced metadata for project name %s. Fix your '
+                    '#egg=%s fragments.',
+                    self.name, metadata_name, self.name
+                )
+                self.req = Requirement(metadata_name)
+
+    def prepare_pep517_metadata(self):
+        # type: () -> None
+        assert self.pep517_backend is not None
+
+        metadata_dir = os.path.join(
+            self.setup_py_dir,
+            'pip-wheel-metadata'
+        )
+        ensure_dir(metadata_dir)
+
+        with self.build_env:
+            # Note that Pep517HookCaller implements a fallback for
+            # prepare_metadata_for_build_wheel, so we don't have to
+            # consider the possibility that this hook doesn't exist.
+            backend = self.pep517_backend
+            self.spin_message = "Preparing wheel metadata"
+            distinfo_dir = backend.prepare_metadata_for_build_wheel(
+                metadata_dir
+            )
+
+        self.metadata_directory = os.path.join(metadata_dir, distinfo_dir)
+
+    def run_egg_info(self):
+        # type: () -> None
+        if self.name:
+            logger.debug(
+                'Running setup.py (path:%s) egg_info for package %s',
+                self.setup_py, self.name,
+            )
+        else:
+            logger.debug(
+                'Running setup.py (path:%s) egg_info for package from %s',
+                self.setup_py, self.link,
+            )
+        script = SETUPTOOLS_SHIM % self.setup_py
+        base_cmd = [sys.executable, '-c', script]
+        if self.isolated:
+            base_cmd += ["--no-user-cfg"]
+        egg_info_cmd = base_cmd + ['egg_info']
+        # We can't put the .egg-info files at the root, because then the
+        # source code will be mistaken for an installed egg, causing
+        # problems
+        if self.editable:
+            egg_base_option = []  # type: List[str]
+        else:
+            egg_info_dir = os.path.join(self.setup_py_dir, 'pip-egg-info')
+            ensure_dir(egg_info_dir)
+            egg_base_option = ['--egg-base', 'pip-egg-info']
+        with self.build_env:
+            call_subprocess(
+                egg_info_cmd + egg_base_option,
+                cwd=self.setup_py_dir,
+                show_stdout=False,
+                command_desc='python setup.py egg_info')
+
+    @property
+    def egg_info_path(self):
+        # type: () -> str
+        if self._egg_info_path is None:
+            if self.editable:
+                base = self.source_dir
+            else:
+                base = os.path.join(self.setup_py_dir, 'pip-egg-info')
+            filenames = os.listdir(base)
+            if self.editable:
+                filenames = []
+                for root, dirs, files in os.walk(base):
+                    for dir in vcs.dirnames:
+                        if dir in dirs:
+                            dirs.remove(dir)
+                    # Iterate over a copy of ``dirs``, since mutating
+                    # a list while iterating over it can cause trouble.
+                    # (See https://github.com/pypa/pip/pull/462.)
+                    for dir in list(dirs):
+                        # Don't search in anything that looks like a virtualenv
+                        # environment
+                        if (
+                                os.path.lexists(
+                                    os.path.join(root, dir, 'bin', 'python')
+                                ) or
+                                os.path.exists(
+                                    os.path.join(
+                                        root, dir, 'Scripts', 'Python.exe'
+                                    )
+                                )):
+                            dirs.remove(dir)
+                        # Also don't search through tests
+                        elif dir == 'test' or dir == 'tests':
+                            dirs.remove(dir)
+                    filenames.extend([os.path.join(root, dir)
+                                      for dir in dirs])
+                filenames = [f for f in filenames if f.endswith('.egg-info')]
+
+            if not filenames:
+                raise InstallationError(
+                    "Files/directories not found in %s" % base
+                )
+            # if we have more than one match, we pick the toplevel one.  This
+            # can easily be the case if there is a dist folder which contains
+            # an extracted tarball for testing purposes.
+            if len(filenames) > 1:
+                filenames.sort(
+                    key=lambda x: x.count(os.path.sep) +
+                    (os.path.altsep and x.count(os.path.altsep) or 0)
+                )
+            self._egg_info_path = os.path.join(base, filenames[0])
+        return self._egg_info_path
+
+    @property
+    def metadata(self):
+        if not hasattr(self, '_metadata'):
+            self._metadata = get_metadata(self.get_dist())
+
+        return self._metadata
+
+    def get_dist(self):
+        # type: () -> Distribution
+        """Return a pkg_resources.Distribution for this requirement"""
+        if self.metadata_directory:
+            base_dir, distinfo = os.path.split(self.metadata_directory)
+            metadata = pkg_resources.PathMetadata(
+                base_dir, self.metadata_directory
+            )
+            dist_name = os.path.splitext(distinfo)[0]
+            typ = pkg_resources.DistInfoDistribution
+        else:
+            egg_info = self.egg_info_path.rstrip(os.path.sep)
+            base_dir = os.path.dirname(egg_info)
+            metadata = pkg_resources.PathMetadata(base_dir, egg_info)
+            dist_name = os.path.splitext(os.path.basename(egg_info))[0]
+            # https://github.com/python/mypy/issues/1174
+            typ = pkg_resources.Distribution  # type: ignore
+
+        return typ(
+            base_dir,
+            project_name=dist_name,
+            metadata=metadata,
+        )
+
+    def assert_source_matches_version(self):
+        # type: () -> None
+        assert self.source_dir
+        version = self.metadata['version']
+        if self.req.specifier and version not in self.req.specifier:
+            logger.warning(
+                'Requested %s, but installing version %s',
+                self,
+                version,
+            )
+        else:
+            logger.debug(
+                'Source in %s has version %s, which satisfies requirement %s',
+                display_path(self.source_dir),
+                version,
+                self,
+            )
+
+    # For both source distributions and editables
+    def ensure_has_source_dir(self, parent_dir):
+        # type: (str) -> str
+        """Ensure that a source_dir is set.
+
+        This will create a temporary build dir if the name of the requirement
+        isn't known yet.
+
+        :param parent_dir: The ideal pip parent_dir for the source_dir.
+            Generally src_dir for editables and build_dir for sdists.
+        :return: self.source_dir
+        """
+        if self.source_dir is None:
+            self.source_dir = self.build_location(parent_dir)
+        return self.source_dir
+
+    # For editable installations
+    def install_editable(
+        self,
+        install_options,  # type: List[str]
+        global_options=(),  # type: Sequence[str]
+        prefix=None  # type: Optional[str]
+    ):
+        # type: (...) -> None
+        logger.info('Running setup.py develop for %s', self.name)
+
+        if self.isolated:
+            global_options = list(global_options) + ["--no-user-cfg"]
+
+        if prefix:
+            prefix_param = ['--prefix={}'.format(prefix)]
+            install_options = list(install_options) + prefix_param
+
+        with indent_log():
+            # FIXME: should we do --install-headers here too?
+            with self.build_env:
+                call_subprocess(
+                    [
+                        sys.executable,
+                        '-c',
+                        SETUPTOOLS_SHIM % self.setup_py
+                    ] +
+                    list(global_options) +
+                    ['develop', '--no-deps'] +
+                    list(install_options),
+
+                    cwd=self.setup_py_dir,
+                    show_stdout=False,
+                )
+
+        self.install_succeeded = True
+
+    def update_editable(self, obtain=True):
+        # type: (bool) -> None
+        if not self.link:
+            logger.debug(
+                "Cannot update repository at %s; repository location is "
+                "unknown",
+                self.source_dir,
+            )
+            return
+        assert self.editable
+        assert self.source_dir
+        if self.link.scheme == 'file':
+            # Static paths don't get updated
+            return
+        assert '+' in self.link.url, "bad url: %r" % self.link.url
+        if not self.update:
+            return
+        vc_type, url = self.link.url.split('+', 1)
+        backend = vcs.get_backend(vc_type)
+        if backend:
+            vcs_backend = backend(self.link.url)
+            if obtain:
+                vcs_backend.obtain(self.source_dir)
+            else:
+                vcs_backend.export(self.source_dir)
+        else:
+            assert 0, (
+                'Unexpected version control type (in %s): %s'
+                % (self.link, vc_type))
+
+    # Top-level Actions
+    def uninstall(self, auto_confirm=False, verbose=False,
+                  use_user_site=False):
+        # type: (bool, bool, bool) -> Optional[UninstallPathSet]
+        """
+        Uninstall the distribution currently satisfying this requirement.
+
+        Prompts before removing or modifying files unless
+        ``auto_confirm`` is True.
+
+        Refuses to delete or modify files outside of ``sys.prefix`` -
+        thus uninstallation within a virtual environment can only
+        modify that virtual environment, even if the virtualenv is
+        linked to global site-packages.
+
+        """
+        if not self.check_if_exists(use_user_site):
+            logger.warning("Skipping %s as it is not installed.", self.name)
+            return None
+        dist = self.satisfied_by or self.conflicts_with
+
+        uninstalled_pathset = UninstallPathSet.from_dist(dist)
+        uninstalled_pathset.remove(auto_confirm, verbose)
+        return uninstalled_pathset
+
+    def _clean_zip_name(self, name, prefix):  # only used by archive.
+        assert name.startswith(prefix + os.path.sep), (
+            "name %r doesn't start with prefix %r" % (name, prefix)
+        )
+        name = name[len(prefix) + 1:]
+        name = name.replace(os.path.sep, '/')
+        return name
+
+    def _get_archive_name(self, path, parentdir, rootdir):
+        # type: (str, str, str) -> str
+        path = os.path.join(parentdir, path)
+        name = self._clean_zip_name(path, rootdir)
+        return self.name + '/' + name
+
+    # TODO: Investigate if this should be kept in InstallRequirement
+    #       Seems to be used only when VCS + downloads
+    def archive(self, build_dir):
+        # type: (str) -> None
+        assert self.source_dir
+        create_archive = True
+        archive_name = '%s-%s.zip' % (self.name, self.metadata["version"])
+        archive_path = os.path.join(build_dir, archive_name)
+        if os.path.exists(archive_path):
+            response = ask_path_exists(
+                'The file %s exists. (i)gnore, (w)ipe, (b)ackup, (a)bort ' %
+                display_path(archive_path), ('i', 'w', 'b', 'a'))
+            if response == 'i':
+                create_archive = False
+            elif response == 'w':
+                logger.warning('Deleting %s', display_path(archive_path))
+                os.remove(archive_path)
+            elif response == 'b':
+                dest_file = backup_dir(archive_path)
+                logger.warning(
+                    'Backing up %s to %s',
+                    display_path(archive_path),
+                    display_path(dest_file),
+                )
+                shutil.move(archive_path, dest_file)
+            elif response == 'a':
+                sys.exit(-1)
+        if create_archive:
+            zip = zipfile.ZipFile(
+                archive_path, 'w', zipfile.ZIP_DEFLATED,
+                allowZip64=True
+            )
+            dir = os.path.normcase(os.path.abspath(self.setup_py_dir))
+            for dirpath, dirnames, filenames in os.walk(dir):
+                if 'pip-egg-info' in dirnames:
+                    dirnames.remove('pip-egg-info')
+                for dirname in dirnames:
+                    dir_arcname = self._get_archive_name(dirname,
+                                                         parentdir=dirpath,
+                                                         rootdir=dir)
+                    zipdir = zipfile.ZipInfo(dir_arcname + '/')
+                    zipdir.external_attr = 0x1ED << 16  # 0o755
+                    zip.writestr(zipdir, '')
+                for filename in filenames:
+                    if filename == PIP_DELETE_MARKER_FILENAME:
+                        continue
+                    file_arcname = self._get_archive_name(filename,
+                                                          parentdir=dirpath,
+                                                          rootdir=dir)
+                    filename = os.path.join(dirpath, filename)
+                    zip.write(filename, file_arcname)
+            zip.close()
+            logger.info('Saved %s', display_path(archive_path))
+
+    def install(
+        self,
+        install_options,  # type: List[str]
+        global_options=None,  # type: Optional[Sequence[str]]
+        root=None,  # type: Optional[str]
+        home=None,  # type: Optional[str]
+        prefix=None,  # type: Optional[str]
+        warn_script_location=True,  # type: bool
+        use_user_site=False,  # type: bool
+        pycompile=True  # type: bool
+    ):
+        # type: (...) -> None
+        global_options = global_options if global_options is not None else []
+        if self.editable:
+            self.install_editable(
+                install_options, global_options, prefix=prefix,
+            )
+            return
+        if self.is_wheel:
+            version = wheel.wheel_version(self.source_dir)
+            wheel.check_compatibility(version, self.name)
+
+            self.move_wheel_files(
+                self.source_dir, root=root, prefix=prefix, home=home,
+                warn_script_location=warn_script_location,
+                use_user_site=use_user_site, pycompile=pycompile,
+            )
+            self.install_succeeded = True
+            return
+
+        # Extend the list of global and install options passed on to
+        # the setup.py call with the ones from the requirements file.
+        # Options specified in requirements file override those
+        # specified on the command line, since the last option given
+        # to setup.py is the one that is used.
+        global_options = list(global_options) + \
+            self.options.get('global_options', [])
+        install_options = list(install_options) + \
+            self.options.get('install_options', [])
+
+        if self.isolated:
+            # https://github.com/python/mypy/issues/1174
+            global_options = global_options + ["--no-user-cfg"]  # type: ignore
+
+        with TempDirectory(kind="record") as temp_dir:
+            record_filename = os.path.join(temp_dir.path, 'install-record.txt')
+            install_args = self.get_install_args(
+                global_options, record_filename, root, prefix, pycompile,
+            )
+            msg = 'Running setup.py install for %s' % (self.name,)
+            with open_spinner(msg) as spinner:
+                with indent_log():
+                    with self.build_env:
+                        call_subprocess(
+                            install_args + install_options,
+                            cwd=self.setup_py_dir,
+                            show_stdout=False,
+                            spinner=spinner,
+                        )
+
+            if not os.path.exists(record_filename):
+                logger.debug('Record file %s not found', record_filename)
+                return
+            self.install_succeeded = True
+
+            def prepend_root(path):
+                if root is None or not os.path.isabs(path):
+                    return path
+                else:
+                    return change_root(root, path)
+
+            with open(record_filename) as f:
+                for line in f:
+                    directory = os.path.dirname(line)
+                    if directory.endswith('.egg-info'):
+                        egg_info_dir = prepend_root(directory)
+                        break
+                else:
+                    logger.warning(
+                        'Could not find .egg-info directory in install record'
+                        ' for %s',
+                        self,
+                    )
+                    # FIXME: put the record somewhere
+                    # FIXME: should this be an error?
+                    return
+            new_lines = []
+            with open(record_filename) as f:
+                for line in f:
+                    filename = line.strip()
+                    if os.path.isdir(filename):
+                        filename += os.path.sep
+                    new_lines.append(
+                        os.path.relpath(prepend_root(filename), egg_info_dir)
+                    )
+            new_lines.sort()
+            ensure_dir(egg_info_dir)
+            inst_files_path = os.path.join(egg_info_dir, 'installed-files.txt')
+            with open(inst_files_path, 'w') as f:
+                f.write('\n'.join(new_lines) + '\n')
+
+    def get_install_args(
+        self,
+        global_options,  # type: Sequence[str]
+        record_filename,  # type: str
+        root,  # type: Optional[str]
+        prefix,  # type: Optional[str]
+        pycompile  # type: bool
+    ):
+        # type: (...) -> List[str]
+        install_args = [sys.executable, "-u"]
+        install_args.append('-c')
+        install_args.append(SETUPTOOLS_SHIM % self.setup_py)
+        install_args += list(global_options) + \
+            ['install', '--record', record_filename]
+        install_args += ['--single-version-externally-managed']
+
+        if root is not None:
+            install_args += ['--root', root]
+        if prefix is not None:
+            install_args += ['--prefix', prefix]
+
+        if pycompile:
+            install_args += ["--compile"]
+        else:
+            install_args += ["--no-compile"]
+
+        if running_under_virtualenv():
+            py_ver_str = 'python' + sysconfig.get_python_version()
+            install_args += ['--install-headers',
+                             os.path.join(sys.prefix, 'include', 'site',
+                                          py_ver_str, self.name)]
+
+        return install_args
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_set.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_set.py
new file mode 100644
index 0000000..d1410e9
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_set.py
@@ -0,0 +1,197 @@
+from __future__ import absolute_import
+
+import logging
+from collections import OrderedDict
+
+from pip._internal.exceptions import InstallationError
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.wheel import Wheel
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, List, Tuple, Dict, Iterable  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+
+
+logger = logging.getLogger(__name__)
+
+
+class RequirementSet(object):
+
+    def __init__(self, require_hashes=False, check_supported_wheels=True):
+        # type: (bool, bool) -> None
+        """Create a RequirementSet.
+        """
+
+        self.requirements = OrderedDict()  # type: Dict[str, InstallRequirement]  # noqa: E501
+        self.require_hashes = require_hashes
+        self.check_supported_wheels = check_supported_wheels
+
+        # Mapping of alias: real_name
+        self.requirement_aliases = {}  # type: Dict[str, str]
+        self.unnamed_requirements = []  # type: List[InstallRequirement]
+        self.successfully_downloaded = []  # type: List[InstallRequirement]
+        self.reqs_to_cleanup = []  # type: List[InstallRequirement]
+
+    def __str__(self):
+        reqs = [req for req in self.requirements.values()
+                if not req.comes_from]
+        reqs.sort(key=lambda req: req.name.lower())
+        return ' '.join([str(req.req) for req in reqs])
+
+    def __repr__(self):
+        reqs = [req for req in self.requirements.values()]
+        reqs.sort(key=lambda req: req.name.lower())
+        reqs_str = ', '.join([str(req.req) for req in reqs])
+        return ('<%s object; %d requirement(s): %s>'
+                % (self.__class__.__name__, len(reqs), reqs_str))
+
+    def add_requirement(
+        self,
+        install_req,  # type: InstallRequirement
+        parent_req_name=None,  # type: Optional[str]
+        extras_requested=None  # type: Optional[Iterable[str]]
+    ):
+        # type: (...) -> Tuple[List[InstallRequirement], Optional[InstallRequirement]]  # noqa: E501
+        """Add install_req as a requirement to install.
+
+        :param parent_req_name: The name of the requirement that needed this
+            added. The name is used because when multiple unnamed requirements
+            resolve to the same name, we could otherwise end up with dependency
+            links that point outside the Requirements set. parent_req must
+            already be added. Note that None implies that this is a user
+            supplied requirement, vs an inferred one.
+        :param extras_requested: an iterable of extras used to evaluate the
+            environment markers.
+        :return: Additional requirements to scan. That is either [] if
+            the requirement is not applicable, or [install_req] if the
+            requirement is applicable and has just been added.
+        """
+        name = install_req.name
+
+        # If the markers do not match, ignore this requirement.
+        if not install_req.match_markers(extras_requested):
+            logger.info(
+                "Ignoring %s: markers '%s' don't match your environment",
+                name, install_req.markers,
+            )
+            return [], None
+
+        # If the wheel is not supported, raise an error.
+        # Should check this after filtering out based on environment markers to
+        # allow specifying different wheels based on the environment/OS, in a
+        # single requirements file.
+        if install_req.link and install_req.link.is_wheel:
+            wheel = Wheel(install_req.link.filename)
+            if self.check_supported_wheels and not wheel.supported():
+                raise InstallationError(
+                    "%s is not a supported wheel on this platform." %
+                    wheel.filename
+                )
+
+        # This next bit is really a sanity check.
+        assert install_req.is_direct == (parent_req_name is None), (
+            "a direct req shouldn't have a parent and also, "
+            "a non direct req should have a parent"
+        )
+
+        # Unnamed requirements are scanned again and the requirement won't be
+        # added as a dependency until after scanning.
+        if not name:
+            # url or path requirement w/o an egg fragment
+            self.unnamed_requirements.append(install_req)
+            return [install_req], None
+
+        try:
+            existing_req = self.get_requirement(name)
+        except KeyError:
+            existing_req = None
+
+        has_conflicting_requirement = (
+            parent_req_name is None and
+            existing_req and
+            not existing_req.constraint and
+            existing_req.extras == install_req.extras and
+            existing_req.req.specifier != install_req.req.specifier
+        )
+        if has_conflicting_requirement:
+            raise InstallationError(
+                "Double requirement given: %s (already in %s, name=%r)"
+                % (install_req, existing_req, name)
+            )
+
+        # When no existing requirement exists, add the requirement as a
+        # dependency and it will be scanned again after.
+        if not existing_req:
+            self.requirements[name] = install_req
+            # FIXME: what about other normalizations?  E.g., _ vs. -?
+            if name.lower() != name:
+                self.requirement_aliases[name.lower()] = name
+            # We'd want to rescan this requirements later
+            return [install_req], install_req
+
+        # Assume there's no need to scan, and that we've already
+        # encountered this for scanning.
+        if install_req.constraint or not existing_req.constraint:
+            return [], existing_req
+
+        does_not_satisfy_constraint = (
+            install_req.link and
+            not (
+                existing_req.link and
+                install_req.link.path == existing_req.link.path
+            )
+        )
+        if does_not_satisfy_constraint:
+            self.reqs_to_cleanup.append(install_req)
+            raise InstallationError(
+                "Could not satisfy constraints for '%s': "
+                "installation from path or url cannot be "
+                "constrained to a version" % name,
+            )
+        # If we're now installing a constraint, mark the existing
+        # object for real installation.
+        existing_req.constraint = False
+        existing_req.extras = tuple(sorted(
+            set(existing_req.extras) | set(install_req.extras)
+        ))
+        logger.debug(
+            "Setting %s extras to: %s",
+            existing_req, existing_req.extras,
+        )
+        # Return the existing requirement for addition to the parent and
+        # scanning again.
+        return [existing_req], existing_req
+
+    def has_requirement(self, project_name):
+        # type: (str) -> bool
+        name = project_name.lower()
+        if (name in self.requirements and
+           not self.requirements[name].constraint or
+           name in self.requirement_aliases and
+           not self.requirements[self.requirement_aliases[name]].constraint):
+            return True
+        return False
+
+    @property
+    def has_requirements(self):
+        # type: () -> List[InstallRequirement]
+        return list(req for req in self.requirements.values() if not
+                    req.constraint) or self.unnamed_requirements
+
+    def get_requirement(self, project_name):
+        # type: (str) -> InstallRequirement
+        for name in project_name, project_name.lower():
+            if name in self.requirements:
+                return self.requirements[name]
+            if name in self.requirement_aliases:
+                return self.requirements[self.requirement_aliases[name]]
+        raise KeyError("No project with the name %r" % project_name)
+
+    def cleanup_files(self):
+        # type: () -> None
+        """Clean up files, remove builds."""
+        logger.debug('Cleaning up...')
+        with indent_log():
+            for req in self.reqs_to_cleanup:
+                req.remove_temporary_source()
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_tracker.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_tracker.py
new file mode 100644
index 0000000..82e084a
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_tracker.py
@@ -0,0 +1,88 @@
+from __future__ import absolute_import
+
+import contextlib
+import errno
+import hashlib
+import logging
+import os
+
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Set, Iterator  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+    from pip._internal.models.link import Link  # noqa: F401
+
+logger = logging.getLogger(__name__)
+
+
+class RequirementTracker(object):
+
+    def __init__(self):
+        # type: () -> None
+        self._root = os.environ.get('PIP_REQ_TRACKER')
+        if self._root is None:
+            self._temp_dir = TempDirectory(delete=False, kind='req-tracker')
+            self._temp_dir.create()
+            self._root = os.environ['PIP_REQ_TRACKER'] = self._temp_dir.path
+            logger.debug('Created requirements tracker %r', self._root)
+        else:
+            self._temp_dir = None
+            logger.debug('Re-using requirements tracker %r', self._root)
+        self._entries = set()  # type: Set[InstallRequirement]
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.cleanup()
+
+    def _entry_path(self, link):
+        # type: (Link) -> str
+        hashed = hashlib.sha224(link.url_without_fragment.encode()).hexdigest()
+        return os.path.join(self._root, hashed)
+
+    def add(self, req):
+        # type: (InstallRequirement) -> None
+        link = req.link
+        info = str(req)
+        entry_path = self._entry_path(link)
+        try:
+            with open(entry_path) as fp:
+                # Error, these's already a build in progress.
+                raise LookupError('%s is already being built: %s'
+                                  % (link, fp.read()))
+        except IOError as e:
+            if e.errno != errno.ENOENT:
+                raise
+            assert req not in self._entries
+            with open(entry_path, 'w') as fp:
+                fp.write(info)
+            self._entries.add(req)
+            logger.debug('Added %s to build tracker %r', req, self._root)
+
+    def remove(self, req):
+        # type: (InstallRequirement) -> None
+        link = req.link
+        self._entries.remove(req)
+        os.unlink(self._entry_path(link))
+        logger.debug('Removed %s from build tracker %r', req, self._root)
+
+    def cleanup(self):
+        # type: () -> None
+        for req in set(self._entries):
+            self.remove(req)
+        remove = self._temp_dir is not None
+        if remove:
+            self._temp_dir.cleanup()
+        logger.debug('%s build tracker %r',
+                     'Removed' if remove else 'Cleaned',
+                     self._root)
+
+    @contextlib.contextmanager
+    def track(self, req):
+        # type: (InstallRequirement) -> Iterator[None]
+        self.add(req)
+        yield
+        self.remove(req)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_uninstall.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_uninstall.py
new file mode 100644
index 0000000..c80959e
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/req/req_uninstall.py
@@ -0,0 +1,596 @@
+from __future__ import absolute_import
+
+import csv
+import functools
+import logging
+import os
+import sys
+import sysconfig
+
+from pip._vendor import pkg_resources
+
+from pip._internal.exceptions import UninstallationError
+from pip._internal.locations import bin_py, bin_user
+from pip._internal.utils.compat import WINDOWS, cache_from_source, uses_pycache
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    FakeFile, ask, dist_in_usersite, dist_is_local, egg_link_path, is_local,
+    normalize_path, renames, rmtree,
+)
+from pip._internal.utils.temp_dir import AdjacentTempDirectory, TempDirectory
+
+logger = logging.getLogger(__name__)
+
+
+def _script_names(dist, script_name, is_gui):
+    """Create the fully qualified name of the files created by
+    {console,gui}_scripts for the given ``dist``.
+    Returns the list of file names
+    """
+    if dist_in_usersite(dist):
+        bin_dir = bin_user
+    else:
+        bin_dir = bin_py
+    exe_name = os.path.join(bin_dir, script_name)
+    paths_to_remove = [exe_name]
+    if WINDOWS:
+        paths_to_remove.append(exe_name + '.exe')
+        paths_to_remove.append(exe_name + '.exe.manifest')
+        if is_gui:
+            paths_to_remove.append(exe_name + '-script.pyw')
+        else:
+            paths_to_remove.append(exe_name + '-script.py')
+    return paths_to_remove
+
+
+def _unique(fn):
+    @functools.wraps(fn)
+    def unique(*args, **kw):
+        seen = set()
+        for item in fn(*args, **kw):
+            if item not in seen:
+                seen.add(item)
+                yield item
+    return unique
+
+
+@_unique
+def uninstallation_paths(dist):
+    """
+    Yield all the uninstallation paths for dist based on RECORD-without-.py[co]
+
+    Yield paths to all the files in RECORD. For each .py file in RECORD, add
+    the .pyc and .pyo in the same directory.
+
+    UninstallPathSet.add() takes care of the __pycache__ .py[co].
+    """
+    r = csv.reader(FakeFile(dist.get_metadata_lines('RECORD')))
+    for row in r:
+        path = os.path.join(dist.location, row[0])
+        yield path
+        if path.endswith('.py'):
+            dn, fn = os.path.split(path)
+            base = fn[:-3]
+            path = os.path.join(dn, base + '.pyc')
+            yield path
+            path = os.path.join(dn, base + '.pyo')
+            yield path
+
+
+def compact(paths):
+    """Compact a path set to contain the minimal number of paths
+    necessary to contain all paths in the set. If /a/path/ and
+    /a/path/to/a/file.txt are both in the set, leave only the
+    shorter path."""
+
+    sep = os.path.sep
+    short_paths = set()
+    for path in sorted(paths, key=len):
+        should_skip = any(
+            path.startswith(shortpath.rstrip("*")) and
+            path[len(shortpath.rstrip("*").rstrip(sep))] == sep
+            for shortpath in short_paths
+        )
+        if not should_skip:
+            short_paths.add(path)
+    return short_paths
+
+
+def compress_for_rename(paths):
+    """Returns a set containing the paths that need to be renamed.
+
+    This set may include directories when the original sequence of paths
+    included every file on disk.
+    """
+    case_map = dict((os.path.normcase(p), p) for p in paths)
+    remaining = set(case_map)
+    unchecked = sorted(set(os.path.split(p)[0]
+                           for p in case_map.values()), key=len)
+    wildcards = set()
+
+    def norm_join(*a):
+        return os.path.normcase(os.path.join(*a))
+
+    for root in unchecked:
+        if any(os.path.normcase(root).startswith(w)
+               for w in wildcards):
+            # This directory has already been handled.
+            continue
+
+        all_files = set()
+        all_subdirs = set()
+        for dirname, subdirs, files in os.walk(root):
+            all_subdirs.update(norm_join(root, dirname, d)
+                               for d in subdirs)
+            all_files.update(norm_join(root, dirname, f)
+                             for f in files)
+        # If all the files we found are in our remaining set of files to
+        # remove, then remove them from the latter set and add a wildcard
+        # for the directory.
+        if not (all_files - remaining):
+            remaining.difference_update(all_files)
+            wildcards.add(root + os.sep)
+
+    return set(map(case_map.__getitem__, remaining)) | wildcards
+
+
+def compress_for_output_listing(paths):
+    """Returns a tuple of 2 sets of which paths to display to user
+
+    The first set contains paths that would be deleted. Files of a package
+    are not added and the top-level directory of the package has a '*' added
+    at the end - to signify that all it's contents are removed.
+
+    The second set contains files that would have been skipped in the above
+    folders.
+    """
+
+    will_remove = list(paths)
+    will_skip = set()
+
+    # Determine folders and files
+    folders = set()
+    files = set()
+    for path in will_remove:
+        if path.endswith(".pyc"):
+            continue
+        if path.endswith("__init__.py") or ".dist-info" in path:
+            folders.add(os.path.dirname(path))
+        files.add(path)
+
+    _normcased_files = set(map(os.path.normcase, files))
+
+    folders = compact(folders)
+
+    # This walks the tree using os.walk to not miss extra folders
+    # that might get added.
+    for folder in folders:
+        for dirpath, _, dirfiles in os.walk(folder):
+            for fname in dirfiles:
+                if fname.endswith(".pyc"):
+                    continue
+
+                file_ = os.path.join(dirpath, fname)
+                if (os.path.isfile(file_) and
+                        os.path.normcase(file_) not in _normcased_files):
+                    # We are skipping this file. Add it to the set.
+                    will_skip.add(file_)
+
+    will_remove = files | {
+        os.path.join(folder, "*") for folder in folders
+    }
+
+    return will_remove, will_skip
+
+
+class StashedUninstallPathSet(object):
+    """A set of file rename operations to stash files while
+    tentatively uninstalling them."""
+    def __init__(self):
+        # Mapping from source file root to [Adjacent]TempDirectory
+        # for files under that directory.
+        self._save_dirs = {}
+        # (old path, new path) tuples for each move that may need
+        # to be undone.
+        self._moves = []
+
+    def _get_directory_stash(self, path):
+        """Stashes a directory.
+
+        Directories are stashed adjacent to their original location if
+        possible, or else moved/copied into the user's temp dir."""
+
+        try:
+            save_dir = AdjacentTempDirectory(path)
+            save_dir.create()
+        except OSError:
+            save_dir = TempDirectory(kind="uninstall")
+            save_dir.create()
+        self._save_dirs[os.path.normcase(path)] = save_dir
+
+        return save_dir.path
+
+    def _get_file_stash(self, path):
+        """Stashes a file.
+
+        If no root has been provided, one will be created for the directory
+        in the user's temp directory."""
+        path = os.path.normcase(path)
+        head, old_head = os.path.dirname(path), None
+        save_dir = None
+
+        while head != old_head:
+            try:
+                save_dir = self._save_dirs[head]
+                break
+            except KeyError:
+                pass
+            head, old_head = os.path.dirname(head), head
+        else:
+            # Did not find any suitable root
+            head = os.path.dirname(path)
+            save_dir = TempDirectory(kind='uninstall')
+            save_dir.create()
+            self._save_dirs[head] = save_dir
+
+        relpath = os.path.relpath(path, head)
+        if relpath and relpath != os.path.curdir:
+            return os.path.join(save_dir.path, relpath)
+        return save_dir.path
+
+    def stash(self, path):
+        """Stashes the directory or file and returns its new location.
+        """
+        if os.path.isdir(path):
+            new_path = self._get_directory_stash(path)
+        else:
+            new_path = self._get_file_stash(path)
+
+        self._moves.append((path, new_path))
+        if os.path.isdir(path) and os.path.isdir(new_path):
+            # If we're moving a directory, we need to
+            # remove the destination first or else it will be
+            # moved to inside the existing directory.
+            # We just created new_path ourselves, so it will
+            # be removable.
+            os.rmdir(new_path)
+        renames(path, new_path)
+        return new_path
+
+    def commit(self):
+        """Commits the uninstall by removing stashed files."""
+        for _, save_dir in self._save_dirs.items():
+            save_dir.cleanup()
+        self._moves = []
+        self._save_dirs = {}
+
+    def rollback(self):
+        """Undoes the uninstall by moving stashed files back."""
+        for p in self._moves:
+            logging.info("Moving to %s\n from %s", *p)
+
+        for new_path, path in self._moves:
+            try:
+                logger.debug('Replacing %s from %s', new_path, path)
+                if os.path.isfile(new_path):
+                    os.unlink(new_path)
+                elif os.path.isdir(new_path):
+                    rmtree(new_path)
+                renames(path, new_path)
+            except OSError as ex:
+                logger.error("Failed to restore %s", new_path)
+                logger.debug("Exception: %s", ex)
+
+        self.commit()
+
+    @property
+    def can_rollback(self):
+        return bool(self._moves)
+
+
+class UninstallPathSet(object):
+    """A set of file paths to be removed in the uninstallation of a
+    requirement."""
+    def __init__(self, dist):
+        self.paths = set()
+        self._refuse = set()
+        self.pth = {}
+        self.dist = dist
+        self._moved_paths = StashedUninstallPathSet()
+
+    def _permitted(self, path):
+        """
+        Return True if the given path is one we are permitted to
+        remove/modify, False otherwise.
+
+        """
+        return is_local(path)
+
+    def add(self, path):
+        head, tail = os.path.split(path)
+
+        # we normalize the head to resolve parent directory symlinks, but not
+        # the tail, since we only want to uninstall symlinks, not their targets
+        path = os.path.join(normalize_path(head), os.path.normcase(tail))
+
+        if not os.path.exists(path):
+            return
+        if self._permitted(path):
+            self.paths.add(path)
+        else:
+            self._refuse.add(path)
+
+        # __pycache__ files can show up after 'installed-files.txt' is created,
+        # due to imports
+        if os.path.splitext(path)[1] == '.py' and uses_pycache:
+            self.add(cache_from_source(path))
+
+    def add_pth(self, pth_file, entry):
+        pth_file = normalize_path(pth_file)
+        if self._permitted(pth_file):
+            if pth_file not in self.pth:
+                self.pth[pth_file] = UninstallPthEntries(pth_file)
+            self.pth[pth_file].add(entry)
+        else:
+            self._refuse.add(pth_file)
+
+    def remove(self, auto_confirm=False, verbose=False):
+        """Remove paths in ``self.paths`` with confirmation (unless
+        ``auto_confirm`` is True)."""
+
+        if not self.paths:
+            logger.info(
+                "Can't uninstall '%s'. No files were found to uninstall.",
+                self.dist.project_name,
+            )
+            return
+
+        dist_name_version = (
+            self.dist.project_name + "-" + self.dist.version
+        )
+        logger.info('Uninstalling %s:', dist_name_version)
+
+        with indent_log():
+            if auto_confirm or self._allowed_to_proceed(verbose):
+                moved = self._moved_paths
+
+                for_rename = compress_for_rename(self.paths)
+
+                for path in sorted(compact(for_rename)):
+                    moved.stash(path)
+                    logger.debug('Removing file or directory %s', path)
+
+                for pth in self.pth.values():
+                    pth.remove()
+
+                logger.info('Successfully uninstalled %s', dist_name_version)
+
+    def _allowed_to_proceed(self, verbose):
+        """Display which files would be deleted and prompt for confirmation
+        """
+
+        def _display(msg, paths):
+            if not paths:
+                return
+
+            logger.info(msg)
+            with indent_log():
+                for path in sorted(compact(paths)):
+                    logger.info(path)
+
+        if not verbose:
+            will_remove, will_skip = compress_for_output_listing(self.paths)
+        else:
+            # In verbose mode, display all the files that are going to be
+            # deleted.
+            will_remove = list(self.paths)
+            will_skip = set()
+
+        _display('Would remove:', will_remove)
+        _display('Would not remove (might be manually added):', will_skip)
+        _display('Would not remove (outside of prefix):', self._refuse)
+        if verbose:
+            _display('Will actually move:', compress_for_rename(self.paths))
+
+        return ask('Proceed (y/n)? ', ('y', 'n')) == 'y'
+
+    def rollback(self):
+        """Rollback the changes previously made by remove()."""
+        if not self._moved_paths.can_rollback:
+            logger.error(
+                "Can't roll back %s; was not uninstalled",
+                self.dist.project_name,
+            )
+            return False
+        logger.info('Rolling back uninstall of %s', self.dist.project_name)
+        self._moved_paths.rollback()
+        for pth in self.pth.values():
+            pth.rollback()
+
+    def commit(self):
+        """Remove temporary save dir: rollback will no longer be possible."""
+        self._moved_paths.commit()
+
+    @classmethod
+    def from_dist(cls, dist):
+        dist_path = normalize_path(dist.location)
+        if not dist_is_local(dist):
+            logger.info(
+                "Not uninstalling %s at %s, outside environment %s",
+                dist.key,
+                dist_path,
+                sys.prefix,
+            )
+            return cls(dist)
+
+        if dist_path in {p for p in {sysconfig.get_path("stdlib"),
+                                     sysconfig.get_path("platstdlib")}
+                         if p}:
+            logger.info(
+                "Not uninstalling %s at %s, as it is in the standard library.",
+                dist.key,
+                dist_path,
+            )
+            return cls(dist)
+
+        paths_to_remove = cls(dist)
+        develop_egg_link = egg_link_path(dist)
+        develop_egg_link_egg_info = '{}.egg-info'.format(
+            pkg_resources.to_filename(dist.project_name))
+        egg_info_exists = dist.egg_info and os.path.exists(dist.egg_info)
+        # Special case for distutils installed package
+        distutils_egg_info = getattr(dist._provider, 'path', None)
+
+        # Uninstall cases order do matter as in the case of 2 installs of the
+        # same package, pip needs to uninstall the currently detected version
+        if (egg_info_exists and dist.egg_info.endswith('.egg-info') and
+                not dist.egg_info.endswith(develop_egg_link_egg_info)):
+            # if dist.egg_info.endswith(develop_egg_link_egg_info), we
+            # are in fact in the develop_egg_link case
+            paths_to_remove.add(dist.egg_info)
+            if dist.has_metadata('installed-files.txt'):
+                for installed_file in dist.get_metadata(
+                        'installed-files.txt').splitlines():
+                    path = os.path.normpath(
+                        os.path.join(dist.egg_info, installed_file)
+                    )
+                    paths_to_remove.add(path)
+            # FIXME: need a test for this elif block
+            # occurs with --single-version-externally-managed/--record outside
+            # of pip
+            elif dist.has_metadata('top_level.txt'):
+                if dist.has_metadata('namespace_packages.txt'):
+                    namespaces = dist.get_metadata('namespace_packages.txt')
+                else:
+                    namespaces = []
+                for top_level_pkg in [
+                        p for p
+                        in dist.get_metadata('top_level.txt').splitlines()
+                        if p and p not in namespaces]:
+                    path = os.path.join(dist.location, top_level_pkg)
+                    paths_to_remove.add(path)
+                    paths_to_remove.add(path + '.py')
+                    paths_to_remove.add(path + '.pyc')
+                    paths_to_remove.add(path + '.pyo')
+
+        elif distutils_egg_info:
+            raise UninstallationError(
+                "Cannot uninstall {!r}. It is a distutils installed project "
+                "and thus we cannot accurately determine which files belong "
+                "to it which would lead to only a partial uninstall.".format(
+                    dist.project_name,
+                )
+            )
+
+        elif dist.location.endswith('.egg'):
+            # package installed by easy_install
+            # We cannot match on dist.egg_name because it can slightly vary
+            # i.e. setuptools-0.6c11-py2.6.egg vs setuptools-0.6rc11-py2.6.egg
+            paths_to_remove.add(dist.location)
+            easy_install_egg = os.path.split(dist.location)[1]
+            easy_install_pth = os.path.join(os.path.dirname(dist.location),
+                                            'easy-install.pth')
+            paths_to_remove.add_pth(easy_install_pth, './' + easy_install_egg)
+
+        elif egg_info_exists and dist.egg_info.endswith('.dist-info'):
+            for path in uninstallation_paths(dist):
+                paths_to_remove.add(path)
+
+        elif develop_egg_link:
+            # develop egg
+            with open(develop_egg_link, 'r') as fh:
+                link_pointer = os.path.normcase(fh.readline().strip())
+            assert (link_pointer == dist.location), (
+                'Egg-link %s does not match installed location of %s '
+                '(at %s)' % (link_pointer, dist.project_name, dist.location)
+            )
+            paths_to_remove.add(develop_egg_link)
+            easy_install_pth = os.path.join(os.path.dirname(develop_egg_link),
+                                            'easy-install.pth')
+            paths_to_remove.add_pth(easy_install_pth, dist.location)
+
+        else:
+            logger.debug(
+                'Not sure how to uninstall: %s - Check: %s',
+                dist, dist.location,
+            )
+
+        # find distutils scripts= scripts
+        if dist.has_metadata('scripts') and dist.metadata_isdir('scripts'):
+            for script in dist.metadata_listdir('scripts'):
+                if dist_in_usersite(dist):
+                    bin_dir = bin_user
+                else:
+                    bin_dir = bin_py
+                paths_to_remove.add(os.path.join(bin_dir, script))
+                if WINDOWS:
+                    paths_to_remove.add(os.path.join(bin_dir, script) + '.bat')
+
+        # find console_scripts
+        _scripts_to_remove = []
+        console_scripts = dist.get_entry_map(group='console_scripts')
+        for name in console_scripts.keys():
+            _scripts_to_remove.extend(_script_names(dist, name, False))
+        # find gui_scripts
+        gui_scripts = dist.get_entry_map(group='gui_scripts')
+        for name in gui_scripts.keys():
+            _scripts_to_remove.extend(_script_names(dist, name, True))
+
+        for s in _scripts_to_remove:
+            paths_to_remove.add(s)
+
+        return paths_to_remove
+
+
+class UninstallPthEntries(object):
+    def __init__(self, pth_file):
+        if not os.path.isfile(pth_file):
+            raise UninstallationError(
+                "Cannot remove entries from nonexistent file %s" % pth_file
+            )
+        self.file = pth_file
+        self.entries = set()
+        self._saved_lines = None
+
+    def add(self, entry):
+        entry = os.path.normcase(entry)
+        # On Windows, os.path.normcase converts the entry to use
+        # backslashes.  This is correct for entries that describe absolute
+        # paths outside of site-packages, but all the others use forward
+        # slashes.
+        if WINDOWS and not os.path.splitdrive(entry)[0]:
+            entry = entry.replace('\\', '/')
+        self.entries.add(entry)
+
+    def remove(self):
+        logger.debug('Removing pth entries from %s:', self.file)
+        with open(self.file, 'rb') as fh:
+            # windows uses '\r\n' with py3k, but uses '\n' with py2.x
+            lines = fh.readlines()
+            self._saved_lines = lines
+        if any(b'\r\n' in line for line in lines):
+            endline = '\r\n'
+        else:
+            endline = '\n'
+        # handle missing trailing newline
+        if lines and not lines[-1].endswith(endline.encode("utf-8")):
+            lines[-1] = lines[-1] + endline.encode("utf-8")
+        for entry in self.entries:
+            try:
+                logger.debug('Removing entry: %s', entry)
+                lines.remove((entry + endline).encode("utf-8"))
+            except ValueError:
+                pass
+        with open(self.file, 'wb') as fh:
+            fh.writelines(lines)
+
+    def rollback(self):
+        if self._saved_lines is None:
+            logger.error(
+                'Cannot roll back changes to %s, none were made', self.file
+            )
+            return False
+        logger.debug('Rolling %s back to previous state', self.file)
+        with open(self.file, 'wb') as fh:
+            fh.writelines(self._saved_lines)
+        return True
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/resolve.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/resolve.py
new file mode 100644
index 0000000..33f572f
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/resolve.py
@@ -0,0 +1,393 @@
+"""Dependency Resolution
+
+The dependency resolution in pip is performed as follows:
+
+for top-level requirements:
+    a. only one spec allowed per project, regardless of conflicts or not.
+       otherwise a "double requirement" exception is raised
+    b. they override sub-dependency requirements.
+for sub-dependencies
+    a. "first found, wins" (where the order is breadth first)
+"""
+
+import logging
+from collections import defaultdict
+from itertools import chain
+
+from pip._internal.exceptions import (
+    BestVersionAlreadyInstalled, DistributionNotFound, HashError, HashErrors,
+    UnsupportedPythonVersion,
+)
+from pip._internal.req.constructors import install_req_from_req_string
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import dist_in_usersite, ensure_dir
+from pip._internal.utils.packaging import check_dist_requires_python
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, DefaultDict, List, Set  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+    from pip._internal.index import PackageFinder  # noqa: F401
+    from pip._internal.req.req_set import RequirementSet  # noqa: F401
+    from pip._internal.operations.prepare import (  # noqa: F401
+        DistAbstraction, RequirementPreparer
+    )
+    from pip._internal.cache import WheelCache  # noqa: F401
+
+logger = logging.getLogger(__name__)
+
+
+class Resolver(object):
+    """Resolves which packages need to be installed/uninstalled to perform \
+    the requested operation without breaking the requirements of any package.
+    """
+
+    _allowed_strategies = {"eager", "only-if-needed", "to-satisfy-only"}
+
+    def __init__(
+        self,
+        preparer,  # type: RequirementPreparer
+        session,  # type: PipSession
+        finder,  # type: PackageFinder
+        wheel_cache,  # type: Optional[WheelCache]
+        use_user_site,  # type: bool
+        ignore_dependencies,  # type: bool
+        ignore_installed,  # type: bool
+        ignore_requires_python,  # type: bool
+        force_reinstall,  # type: bool
+        isolated,  # type: bool
+        upgrade_strategy,  # type: str
+        use_pep517=None  # type: Optional[bool]
+    ):
+        # type: (...) -> None
+        super(Resolver, self).__init__()
+        assert upgrade_strategy in self._allowed_strategies
+
+        self.preparer = preparer
+        self.finder = finder
+        self.session = session
+
+        # NOTE: This would eventually be replaced with a cache that can give
+        #       information about both sdist and wheels transparently.
+        self.wheel_cache = wheel_cache
+
+        # This is set in resolve
+        self.require_hashes = None  # type: Optional[bool]
+
+        self.upgrade_strategy = upgrade_strategy
+        self.force_reinstall = force_reinstall
+        self.isolated = isolated
+        self.ignore_dependencies = ignore_dependencies
+        self.ignore_installed = ignore_installed
+        self.ignore_requires_python = ignore_requires_python
+        self.use_user_site = use_user_site
+        self.use_pep517 = use_pep517
+
+        self._discovered_dependencies = \
+            defaultdict(list)  # type: DefaultDict[str, List]
+
+    def resolve(self, requirement_set):
+        # type: (RequirementSet) -> None
+        """Resolve what operations need to be done
+
+        As a side-effect of this method, the packages (and their dependencies)
+        are downloaded, unpacked and prepared for installation. This
+        preparation is done by ``pip.operations.prepare``.
+
+        Once PyPI has static dependency metadata available, it would be
+        possible to move the preparation to become a step separated from
+        dependency resolution.
+        """
+        # make the wheelhouse
+        if self.preparer.wheel_download_dir:
+            ensure_dir(self.preparer.wheel_download_dir)
+
+        # If any top-level requirement has a hash specified, enter
+        # hash-checking mode, which requires hashes from all.
+        root_reqs = (
+            requirement_set.unnamed_requirements +
+            list(requirement_set.requirements.values())
+        )
+        self.require_hashes = (
+            requirement_set.require_hashes or
+            any(req.has_hash_options for req in root_reqs)
+        )
+
+        # Display where finder is looking for packages
+        locations = self.finder.get_formatted_locations()
+        if locations:
+            logger.info(locations)
+
+        # Actually prepare the files, and collect any exceptions. Most hash
+        # exceptions cannot be checked ahead of time, because
+        # req.populate_link() needs to be called before we can make decisions
+        # based on link type.
+        discovered_reqs = []  # type: List[InstallRequirement]
+        hash_errors = HashErrors()
+        for req in chain(root_reqs, discovered_reqs):
+            try:
+                discovered_reqs.extend(
+                    self._resolve_one(requirement_set, req)
+                )
+            except HashError as exc:
+                exc.req = req
+                hash_errors.append(exc)
+
+        if hash_errors:
+            raise hash_errors
+
+    def _is_upgrade_allowed(self, req):
+        # type: (InstallRequirement) -> bool
+        if self.upgrade_strategy == "to-satisfy-only":
+            return False
+        elif self.upgrade_strategy == "eager":
+            return True
+        else:
+            assert self.upgrade_strategy == "only-if-needed"
+            return req.is_direct
+
+    def _set_req_to_reinstall(self, req):
+        # type: (InstallRequirement) -> None
+        """
+        Set a requirement to be installed.
+        """
+        # Don't uninstall the conflict if doing a user install and the
+        # conflict is not a user install.
+        if not self.use_user_site or dist_in_usersite(req.satisfied_by):
+            req.conflicts_with = req.satisfied_by
+        req.satisfied_by = None
+
+    # XXX: Stop passing requirement_set for options
+    def _check_skip_installed(self, req_to_install):
+        # type: (InstallRequirement) -> Optional[str]
+        """Check if req_to_install should be skipped.
+
+        This will check if the req is installed, and whether we should upgrade
+        or reinstall it, taking into account all the relevant user options.
+
+        After calling this req_to_install will only have satisfied_by set to
+        None if the req_to_install is to be upgraded/reinstalled etc. Any
+        other value will be a dist recording the current thing installed that
+        satisfies the requirement.
+
+        Note that for vcs urls and the like we can't assess skipping in this
+        routine - we simply identify that we need to pull the thing down,
+        then later on it is pulled down and introspected to assess upgrade/
+        reinstalls etc.
+
+        :return: A text reason for why it was skipped, or None.
+        """
+        if self.ignore_installed:
+            return None
+
+        req_to_install.check_if_exists(self.use_user_site)
+        if not req_to_install.satisfied_by:
+            return None
+
+        if self.force_reinstall:
+            self._set_req_to_reinstall(req_to_install)
+            return None
+
+        if not self._is_upgrade_allowed(req_to_install):
+            if self.upgrade_strategy == "only-if-needed":
+                return 'already satisfied, skipping upgrade'
+            return 'already satisfied'
+
+        # Check for the possibility of an upgrade.  For link-based
+        # requirements we have to pull the tree down and inspect to assess
+        # the version #, so it's handled way down.
+        if not req_to_install.link:
+            try:
+                self.finder.find_requirement(req_to_install, upgrade=True)
+            except BestVersionAlreadyInstalled:
+                # Then the best version is installed.
+                return 'already up-to-date'
+            except DistributionNotFound:
+                # No distribution found, so we squash the error.  It will
+                # be raised later when we re-try later to do the install.
+                # Why don't we just raise here?
+                pass
+
+        self._set_req_to_reinstall(req_to_install)
+        return None
+
+    def _get_abstract_dist_for(self, req):
+        # type: (InstallRequirement) -> DistAbstraction
+        """Takes a InstallRequirement and returns a single AbstractDist \
+        representing a prepared variant of the same.
+        """
+        assert self.require_hashes is not None, (
+            "require_hashes should have been set in Resolver.resolve()"
+        )
+
+        if req.editable:
+            return self.preparer.prepare_editable_requirement(
+                req, self.require_hashes, self.use_user_site, self.finder,
+            )
+
+        # satisfied_by is only evaluated by calling _check_skip_installed,
+        # so it must be None here.
+        assert req.satisfied_by is None
+        skip_reason = self._check_skip_installed(req)
+
+        if req.satisfied_by:
+            return self.preparer.prepare_installed_requirement(
+                req, self.require_hashes, skip_reason
+            )
+
+        upgrade_allowed = self._is_upgrade_allowed(req)
+        abstract_dist = self.preparer.prepare_linked_requirement(
+            req, self.session, self.finder, upgrade_allowed,
+            self.require_hashes
+        )
+
+        # NOTE
+        # The following portion is for determining if a certain package is
+        # going to be re-installed/upgraded or not and reporting to the user.
+        # This should probably get cleaned up in a future refactor.
+
+        # req.req is only avail after unpack for URL
+        # pkgs repeat check_if_exists to uninstall-on-upgrade
+        # (#14)
+        if not self.ignore_installed:
+            req.check_if_exists(self.use_user_site)
+
+        if req.satisfied_by:
+            should_modify = (
+                self.upgrade_strategy != "to-satisfy-only" or
+                self.force_reinstall or
+                self.ignore_installed or
+                req.link.scheme == 'file'
+            )
+            if should_modify:
+                self._set_req_to_reinstall(req)
+            else:
+                logger.info(
+                    'Requirement already satisfied (use --upgrade to upgrade):'
+                    ' %s', req,
+                )
+
+        return abstract_dist
+
+    def _resolve_one(
+        self,
+        requirement_set,  # type: RequirementSet
+        req_to_install  # type: InstallRequirement
+    ):
+        # type: (...) -> List[InstallRequirement]
+        """Prepare a single requirements file.
+
+        :return: A list of additional InstallRequirements to also install.
+        """
+        # Tell user what we are doing for this requirement:
+        # obtain (editable), skipping, processing (local url), collecting
+        # (remote url or package name)
+        if req_to_install.constraint or req_to_install.prepared:
+            return []
+
+        req_to_install.prepared = True
+
+        # register tmp src for cleanup in case something goes wrong
+        requirement_set.reqs_to_cleanup.append(req_to_install)
+
+        abstract_dist = self._get_abstract_dist_for(req_to_install)
+
+        # Parse and return dependencies
+        dist = abstract_dist.dist()
+        try:
+            check_dist_requires_python(dist)
+        except UnsupportedPythonVersion as err:
+            if self.ignore_requires_python:
+                logger.warning(err.args[0])
+            else:
+                raise
+
+        more_reqs = []  # type: List[InstallRequirement]
+
+        def add_req(subreq, extras_requested):
+            sub_install_req = install_req_from_req_string(
+                str(subreq),
+                req_to_install,
+                isolated=self.isolated,
+                wheel_cache=self.wheel_cache,
+                use_pep517=self.use_pep517
+            )
+            parent_req_name = req_to_install.name
+            to_scan_again, add_to_parent = requirement_set.add_requirement(
+                sub_install_req,
+                parent_req_name=parent_req_name,
+                extras_requested=extras_requested,
+            )
+            if parent_req_name and add_to_parent:
+                self._discovered_dependencies[parent_req_name].append(
+                    add_to_parent
+                )
+            more_reqs.extend(to_scan_again)
+
+        with indent_log():
+            # We add req_to_install before its dependencies, so that we
+            # can refer to it when adding dependencies.
+            if not requirement_set.has_requirement(req_to_install.name):
+                # 'unnamed' requirements will get added here
+                req_to_install.is_direct = True
+                requirement_set.add_requirement(
+                    req_to_install, parent_req_name=None,
+                )
+
+            if not self.ignore_dependencies:
+                if req_to_install.extras:
+                    logger.debug(
+                        "Installing extra requirements: %r",
+                        ','.join(req_to_install.extras),
+                    )
+                missing_requested = sorted(
+                    set(req_to_install.extras) - set(dist.extras)
+                )
+                for missing in missing_requested:
+                    logger.warning(
+                        '%s does not provide the extra \'%s\'',
+                        dist, missing
+                    )
+
+                available_requested = sorted(
+                    set(dist.extras) & set(req_to_install.extras)
+                )
+                for subreq in dist.requires(available_requested):
+                    add_req(subreq, extras_requested=available_requested)
+
+            if not req_to_install.editable and not req_to_install.satisfied_by:
+                # XXX: --no-install leads this to report 'Successfully
+                # downloaded' for only non-editable reqs, even though we took
+                # action on them.
+                requirement_set.successfully_downloaded.append(req_to_install)
+
+        return more_reqs
+
+    def get_installation_order(self, req_set):
+        # type: (RequirementSet) -> List[InstallRequirement]
+        """Create the installation order.
+
+        The installation order is topological - requirements are installed
+        before the requiring thing. We break cycles at an arbitrary point,
+        and make no other guarantees.
+        """
+        # The current implementation, which we may change at any point
+        # installs the user specified things in the order given, except when
+        # dependencies must come earlier to achieve topological order.
+        order = []
+        ordered_reqs = set()  # type: Set[InstallRequirement]
+
+        def schedule(req):
+            if req.satisfied_by or req in ordered_reqs:
+                return
+            if req.constraint:
+                return
+            ordered_reqs.add(req)
+            for dep in self._discovered_dependencies[req.name]:
+                schedule(dep)
+            order.append(req)
+
+        for install_req in req_set.requirements.values():
+            schedule(install_req)
+        return order
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/__init__.py
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/appdirs.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/appdirs.py
new file mode 100644
index 0000000..9af9fa7
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/appdirs.py
@@ -0,0 +1,270 @@
+"""
+This code was taken from https://github.com/ActiveState/appdirs and modified
+to suit our purposes.
+"""
+from __future__ import absolute_import
+
+import os
+import sys
+
+from pip._vendor.six import PY2, text_type
+
+from pip._internal.utils.compat import WINDOWS, expanduser
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        List, Union
+    )
+
+
+def user_cache_dir(appname):
+    # type: (str) -> str
+    r"""
+    Return full path to the user-specific cache dir for this application.
+
+        "appname" is the name of application.
+
+    Typical user cache directories are:
+        macOS:      ~/Library/Caches/<AppName>
+        Unix:       ~/.cache/<AppName> (XDG default)
+        Windows:    C:\Users\<username>\AppData\Local\<AppName>\Cache
+
+    On Windows the only suggestion in the MSDN docs is that local settings go
+    in the `CSIDL_LOCAL_APPDATA` directory. This is identical to the
+    non-roaming app data dir (the default returned by `user_data_dir`). Apps
+    typically put cache data somewhere *under* the given dir here. Some
+    examples:
+        ...\Mozilla\Firefox\Profiles\<ProfileName>\Cache
+        ...\Acme\SuperApp\Cache\1.0
+
+    OPINION: This function appends "Cache" to the `CSIDL_LOCAL_APPDATA` value.
+    """
+    if WINDOWS:
+        # Get the base path
+        path = os.path.normpath(_get_win_folder("CSIDL_LOCAL_APPDATA"))
+
+        # When using Python 2, return paths as bytes on Windows like we do on
+        # other operating systems. See helper function docs for more details.
+        if PY2 and isinstance(path, text_type):
+            path = _win_path_to_bytes(path)
+
+        # Add our app name and Cache directory to it
+        path = os.path.join(path, appname, "Cache")
+    elif sys.platform == "darwin":
+        # Get the base path
+        path = expanduser("~/Library/Caches")
+
+        # Add our app name to it
+        path = os.path.join(path, appname)
+    else:
+        # Get the base path
+        path = os.getenv("XDG_CACHE_HOME", expanduser("~/.cache"))
+
+        # Add our app name to it
+        path = os.path.join(path, appname)
+
+    return path
+
+
+def user_data_dir(appname, roaming=False):
+    # type: (str, bool) -> str
+    r"""
+    Return full path to the user-specific data dir for this application.
+
+        "appname" is the name of application.
+            If None, just the system directory is returned.
+        "roaming" (boolean, default False) can be set True to use the Windows
+            roaming appdata directory. That means that for users on a Windows
+            network setup for roaming profiles, this user data will be
+            sync'd on login. See
+            <http://technet.microsoft.com/en-us/library/cc766489(WS.10).aspx>
+            for a discussion of issues.
+
+    Typical user data directories are:
+        macOS:                  ~/Library/Application Support/<AppName>
+                                if it exists, else ~/.config/<AppName>
+        Unix:                   ~/.local/share/<AppName>    # or in
+                                $XDG_DATA_HOME, if defined
+        Win XP (not roaming):   C:\Documents and Settings\<username>\ ...
+                                ...Application Data\<AppName>
+        Win XP (roaming):       C:\Documents and Settings\<username>\Local ...
+                                ...Settings\Application Data\<AppName>
+        Win 7  (not roaming):   C:\\Users\<username>\AppData\Local\<AppName>
+        Win 7  (roaming):       C:\\Users\<username>\AppData\Roaming\<AppName>
+
+    For Unix, we follow the XDG spec and support $XDG_DATA_HOME.
+    That means, by default "~/.local/share/<AppName>".
+    """
+    if WINDOWS:
+        const = roaming and "CSIDL_APPDATA" or "CSIDL_LOCAL_APPDATA"
+        path = os.path.join(os.path.normpath(_get_win_folder(const)), appname)
+    elif sys.platform == "darwin":
+        path = os.path.join(
+            expanduser('~/Library/Application Support/'),
+            appname,
+        ) if os.path.isdir(os.path.join(
+            expanduser('~/Library/Application Support/'),
+            appname,
+        )
+        ) else os.path.join(
+            expanduser('~/.config/'),
+            appname,
+        )
+    else:
+        path = os.path.join(
+            os.getenv('XDG_DATA_HOME', expanduser("~/.local/share")),
+            appname,
+        )
+
+    return path
+
+
+def user_config_dir(appname, roaming=True):
+    # type: (str, bool) -> str
+    """Return full path to the user-specific config dir for this application.
+
+        "appname" is the name of application.
+            If None, just the system directory is returned.
+        "roaming" (boolean, default True) can be set False to not use the
+            Windows roaming appdata directory. That means that for users on a
+            Windows network setup for roaming profiles, this user data will be
+            sync'd on login. See
+            <http://technet.microsoft.com/en-us/library/cc766489(WS.10).aspx>
+            for a discussion of issues.
+
+    Typical user data directories are:
+        macOS:                  same as user_data_dir
+        Unix:                   ~/.config/<AppName>
+        Win *:                  same as user_data_dir
+
+    For Unix, we follow the XDG spec and support $XDG_CONFIG_HOME.
+    That means, by default "~/.config/<AppName>".
+    """
+    if WINDOWS:
+        path = user_data_dir(appname, roaming=roaming)
+    elif sys.platform == "darwin":
+        path = user_data_dir(appname)
+    else:
+        path = os.getenv('XDG_CONFIG_HOME', expanduser("~/.config"))
+        path = os.path.join(path, appname)
+
+    return path
+
+
+# for the discussion regarding site_config_dirs locations
+# see <https://github.com/pypa/pip/issues/1733>
+def site_config_dirs(appname):
+    # type: (str) -> List[str]
+    r"""Return a list of potential user-shared config dirs for this application.
+
+        "appname" is the name of application.
+
+    Typical user config directories are:
+        macOS:      /Library/Application Support/<AppName>/
+        Unix:       /etc or $XDG_CONFIG_DIRS[i]/<AppName>/ for each value in
+                    $XDG_CONFIG_DIRS
+        Win XP:     C:\Documents and Settings\All Users\Application ...
+                    ...Data\<AppName>\
+        Vista:      (Fail! "C:\ProgramData" is a hidden *system* directory
+                    on Vista.)
+        Win 7:      Hidden, but writeable on Win 7:
+                    C:\ProgramData\<AppName>\
+    """
+    if WINDOWS:
+        path = os.path.normpath(_get_win_folder("CSIDL_COMMON_APPDATA"))
+        pathlist = [os.path.join(path, appname)]
+    elif sys.platform == 'darwin':
+        pathlist = [os.path.join('/Library/Application Support', appname)]
+    else:
+        # try looking in $XDG_CONFIG_DIRS
+        xdg_config_dirs = os.getenv('XDG_CONFIG_DIRS', '/etc/xdg')
+        if xdg_config_dirs:
+            pathlist = [
+                os.path.join(expanduser(x), appname)
+                for x in xdg_config_dirs.split(os.pathsep)
+            ]
+        else:
+            pathlist = []
+
+        # always look in /etc directly as well
+        pathlist.append('/etc')
+
+    return pathlist
+
+
+# -- Windows support functions --
+
+def _get_win_folder_from_registry(csidl_name):
+    # type: (str) -> str
+    """
+    This is a fallback technique at best. I'm not sure if using the
+    registry for this guarantees us the correct answer for all CSIDL_*
+    names.
+    """
+    import _winreg
+
+    shell_folder_name = {
+        "CSIDL_APPDATA": "AppData",
+        "CSIDL_COMMON_APPDATA": "Common AppData",
+        "CSIDL_LOCAL_APPDATA": "Local AppData",
+    }[csidl_name]
+
+    key = _winreg.OpenKey(
+        _winreg.HKEY_CURRENT_USER,
+        r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
+    )
+    directory, _type = _winreg.QueryValueEx(key, shell_folder_name)
+    return directory
+
+
+def _get_win_folder_with_ctypes(csidl_name):
+    # type: (str) -> str
+    csidl_const = {
+        "CSIDL_APPDATA": 26,
+        "CSIDL_COMMON_APPDATA": 35,
+        "CSIDL_LOCAL_APPDATA": 28,
+    }[csidl_name]
+
+    buf = ctypes.create_unicode_buffer(1024)
+    ctypes.windll.shell32.SHGetFolderPathW(None, csidl_const, None, 0, buf)
+
+    # Downgrade to short path name if have highbit chars. See
+    # <http://bugs.activestate.com/show_bug.cgi?id=85099>.
+    has_high_char = False
+    for c in buf:
+        if ord(c) > 255:
+            has_high_char = True
+            break
+    if has_high_char:
+        buf2 = ctypes.create_unicode_buffer(1024)
+        if ctypes.windll.kernel32.GetShortPathNameW(buf.value, buf2, 1024):
+            buf = buf2
+
+    return buf.value
+
+
+if WINDOWS:
+    try:
+        import ctypes
+        _get_win_folder = _get_win_folder_with_ctypes
+    except ImportError:
+        _get_win_folder = _get_win_folder_from_registry
+
+
+def _win_path_to_bytes(path):
+    """Encode Windows paths to bytes. Only used on Python 2.
+
+    Motivation is to be consistent with other operating systems where paths
+    are also returned as bytes. This avoids problems mixing bytes and Unicode
+    elsewhere in the codebase. For more details and discussion see
+    <https://github.com/pypa/pip/issues/3463>.
+
+    If encoding using ASCII and MBCS fails, return the original Unicode path.
+    """
+    for encoding in ('ASCII', 'MBCS'):
+        try:
+            return path.encode(encoding)
+        except (UnicodeEncodeError, LookupError):
+            pass
+    return path
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/compat.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/compat.py
new file mode 100644
index 0000000..2d8b3bf
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/compat.py
@@ -0,0 +1,264 @@
+"""Stuff that differs in different Python versions and platform
+distributions."""
+from __future__ import absolute_import, division
+
+import codecs
+import locale
+import logging
+import os
+import shutil
+import sys
+
+from pip._vendor.six import text_type
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Tuple, Text  # noqa: F401
+
+try:
+    import ipaddress
+except ImportError:
+    try:
+        from pip._vendor import ipaddress  # type: ignore
+    except ImportError:
+        import ipaddr as ipaddress  # type: ignore
+        ipaddress.ip_address = ipaddress.IPAddress  # type: ignore
+        ipaddress.ip_network = ipaddress.IPNetwork  # type: ignore
+
+
+__all__ = [
+    "ipaddress", "uses_pycache", "console_to_str", "native_str",
+    "get_path_uid", "stdlib_pkgs", "WINDOWS", "samefile", "get_terminal_size",
+    "get_extension_suffixes",
+]
+
+
+logger = logging.getLogger(__name__)
+
+if sys.version_info >= (3, 4):
+    uses_pycache = True
+    from importlib.util import cache_from_source
+else:
+    import imp
+
+    try:
+        cache_from_source = imp.cache_from_source  # type: ignore
+    except AttributeError:
+        # does not use __pycache__
+        cache_from_source = None
+
+    uses_pycache = cache_from_source is not None
+
+
+if sys.version_info >= (3, 5):
+    backslashreplace_decode = "backslashreplace"
+else:
+    # In version 3.4 and older, backslashreplace exists
+    # but does not support use for decoding.
+    # We implement our own replace handler for this
+    # situation, so that we can consistently use
+    # backslash replacement for all versions.
+    def backslashreplace_decode_fn(err):
+        raw_bytes = (err.object[i] for i in range(err.start, err.end))
+        if sys.version_info[0] == 2:
+            # Python 2 gave us characters - convert to numeric bytes
+            raw_bytes = (ord(b) for b in raw_bytes)
+        return u"".join(u"\\x%x" % c for c in raw_bytes), err.end
+    codecs.register_error(
+        "backslashreplace_decode",
+        backslashreplace_decode_fn,
+    )
+    backslashreplace_decode = "backslashreplace_decode"
+
+
+def console_to_str(data):
+    # type: (bytes) -> Text
+    """Return a string, safe for output, of subprocess output.
+
+    We assume the data is in the locale preferred encoding.
+    If it won't decode properly, we warn the user but decode as
+    best we can.
+
+    We also ensure that the output can be safely written to
+    standard output without encoding errors.
+    """
+
+    # First, get the encoding we assume. This is the preferred
+    # encoding for the locale, unless that is not found, or
+    # it is ASCII, in which case assume UTF-8
+    encoding = locale.getpreferredencoding()
+    if (not encoding) or codecs.lookup(encoding).name == "ascii":
+        encoding = "utf-8"
+
+    # Now try to decode the data - if we fail, warn the user and
+    # decode with replacement.
+    try:
+        decoded_data = data.decode(encoding)
+    except UnicodeDecodeError:
+        logger.warning(
+            "Subprocess output does not appear to be encoded as %s",
+            encoding,
+        )
+        decoded_data = data.decode(encoding, errors=backslashreplace_decode)
+
+    # Make sure we can print the output, by encoding it to the output
+    # encoding with replacement of unencodable characters, and then
+    # decoding again.
+    # We use stderr's encoding because it's less likely to be
+    # redirected and if we don't find an encoding we skip this
+    # step (on the assumption that output is wrapped by something
+    # that won't fail).
+    # The double getattr is to deal with the possibility that we're
+    # being called in a situation where sys.__stderr__ doesn't exist,
+    # or doesn't have an encoding attribute. Neither of these cases
+    # should occur in normal pip use, but there's no harm in checking
+    # in case people use pip in (unsupported) unusual situations.
+    output_encoding = getattr(getattr(sys, "__stderr__", None),
+                              "encoding", None)
+
+    if output_encoding:
+        output_encoded = decoded_data.encode(
+            output_encoding,
+            errors="backslashreplace"
+        )
+        decoded_data = output_encoded.decode(output_encoding)
+
+    return decoded_data
+
+
+if sys.version_info >= (3,):
+    def native_str(s, replace=False):
+        # type: (str, bool) -> str
+        if isinstance(s, bytes):
+            return s.decode('utf-8', 'replace' if replace else 'strict')
+        return s
+
+else:
+    def native_str(s, replace=False):
+        # type: (str, bool) -> str
+        # Replace is ignored -- unicode to UTF-8 can't fail
+        if isinstance(s, text_type):
+            return s.encode('utf-8')
+        return s
+
+
+def get_path_uid(path):
+    # type: (str) -> int
+    """
+    Return path's uid.
+
+    Does not follow symlinks:
+        https://github.com/pypa/pip/pull/935#discussion_r5307003
+
+    Placed this function in compat due to differences on AIX and
+    Jython, that should eventually go away.
+
+    :raises OSError: When path is a symlink or can't be read.
+    """
+    if hasattr(os, 'O_NOFOLLOW'):
+        fd = os.open(path, os.O_RDONLY | os.O_NOFOLLOW)
+        file_uid = os.fstat(fd).st_uid
+        os.close(fd)
+    else:  # AIX and Jython
+        # WARNING: time of check vulnerability, but best we can do w/o NOFOLLOW
+        if not os.path.islink(path):
+            # older versions of Jython don't have `os.fstat`
+            file_uid = os.stat(path).st_uid
+        else:
+            # raise OSError for parity with os.O_NOFOLLOW above
+            raise OSError(
+                "%s is a symlink; Will not return uid for symlinks" % path
+            )
+    return file_uid
+
+
+if sys.version_info >= (3, 4):
+    from importlib.machinery import EXTENSION_SUFFIXES
+
+    def get_extension_suffixes():
+        return EXTENSION_SUFFIXES
+else:
+    from imp import get_suffixes
+
+    def get_extension_suffixes():
+        return [suffix[0] for suffix in get_suffixes()]
+
+
+def expanduser(path):
+    # type: (str) -> str
+    """
+    Expand ~ and ~user constructions.
+
+    Includes a workaround for https://bugs.python.org/issue14768
+    """
+    expanded = os.path.expanduser(path)
+    if path.startswith('~/') and expanded.startswith('//'):
+        expanded = expanded[1:]
+    return expanded
+
+
+# packages in the stdlib that may have installation metadata, but should not be
+# considered 'installed'.  this theoretically could be determined based on
+# dist.location (py27:`sysconfig.get_paths()['stdlib']`,
+# py26:sysconfig.get_config_vars('LIBDEST')), but fear platform variation may
+# make this ineffective, so hard-coding
+stdlib_pkgs = {"python", "wsgiref", "argparse"}
+
+
+# windows detection, covers cpython and ironpython
+WINDOWS = (sys.platform.startswith("win") or
+           (sys.platform == 'cli' and os.name == 'nt'))
+
+
+def samefile(file1, file2):
+    # type: (str, str) -> bool
+    """Provide an alternative for os.path.samefile on Windows/Python2"""
+    if hasattr(os.path, 'samefile'):
+        return os.path.samefile(file1, file2)
+    else:
+        path1 = os.path.normcase(os.path.abspath(file1))
+        path2 = os.path.normcase(os.path.abspath(file2))
+        return path1 == path2
+
+
+if hasattr(shutil, 'get_terminal_size'):
+    def get_terminal_size():
+        # type: () -> Tuple[int, int]
+        """
+        Returns a tuple (x, y) representing the width(x) and the height(y)
+        in characters of the terminal window.
+        """
+        return tuple(shutil.get_terminal_size())  # type: ignore
+else:
+    def get_terminal_size():
+        # type: () -> Tuple[int, int]
+        """
+        Returns a tuple (x, y) representing the width(x) and the height(y)
+        in characters of the terminal window.
+        """
+        def ioctl_GWINSZ(fd):
+            try:
+                import fcntl
+                import termios
+                import struct
+                cr = struct.unpack_from(
+                    'hh',
+                    fcntl.ioctl(fd, termios.TIOCGWINSZ, '12345678')
+                )
+            except Exception:
+                return None
+            if cr == (0, 0):
+                return None
+            return cr
+        cr = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)
+        if not cr:
+            try:
+                fd = os.open(os.ctermid(), os.O_RDONLY)
+                cr = ioctl_GWINSZ(fd)
+                os.close(fd)
+            except Exception:
+                pass
+        if not cr:
+            cr = (os.environ.get('LINES', 25), os.environ.get('COLUMNS', 80))
+        return int(cr[1]), int(cr[0])
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/deprecation.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/deprecation.py
new file mode 100644
index 0000000..0beaf74
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/deprecation.py
@@ -0,0 +1,90 @@
+"""
+A module that implements tooling to enable easy warnings about deprecations.
+"""
+from __future__ import absolute_import
+
+import logging
+import warnings
+
+from pip._vendor.packaging.version import parse
+
+from pip import __version__ as current_version
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Optional  # noqa: F401
+
+
+class PipDeprecationWarning(Warning):
+    pass
+
+
+_original_showwarning = None  # type: Any
+
+
+# Warnings <-> Logging Integration
+def _showwarning(message, category, filename, lineno, file=None, line=None):
+    if file is not None:
+        if _original_showwarning is not None:
+            _original_showwarning(
+                message, category, filename, lineno, file, line,
+            )
+    elif issubclass(category, PipDeprecationWarning):
+        # We use a specially named logger which will handle all of the
+        # deprecation messages for pip.
+        logger = logging.getLogger("pip._internal.deprecations")
+        logger.warning(message)
+    else:
+        _original_showwarning(
+            message, category, filename, lineno, file, line,
+        )
+
+
+def install_warning_logger():
+    # type: () -> None
+    # Enable our Deprecation Warnings
+    warnings.simplefilter("default", PipDeprecationWarning, append=True)
+
+    global _original_showwarning
+
+    if _original_showwarning is None:
+        _original_showwarning = warnings.showwarning
+        warnings.showwarning = _showwarning
+
+
+def deprecated(reason, replacement, gone_in, issue=None):
+    # type: (str, Optional[str], Optional[str], Optional[int]) -> None
+    """Helper to deprecate existing functionality.
+
+    reason:
+        Textual reason shown to the user about why this functionality has
+        been deprecated.
+    replacement:
+        Textual suggestion shown to the user about what alternative
+        functionality they can use.
+    gone_in:
+        The version of pip does this functionality should get removed in.
+        Raises errors if pip's current version is greater than or equal to
+        this.
+    issue:
+        Issue number on the tracker that would serve as a useful place for
+        users to find related discussion and provide feedback.
+
+    Always pass replacement, gone_in and issue as keyword arguments for clarity
+    at the call site.
+    """
+
+    # Construct a nice message.
+    # This is purposely eagerly formatted as we want it to appear as if someone
+    # typed this entire message out.
+    message = "DEPRECATION: " + reason
+    if replacement is not None:
+        message += " A possible replacement is {}.".format(replacement)
+    if issue is not None:
+        url = "https://github.com/pypa/pip/issues/" + str(issue)
+        message += " You can find discussion regarding this at {}.".format(url)
+
+    # Raise as an error if it has to be removed.
+    if gone_in is not None and parse(current_version) >= parse(gone_in):
+        raise PipDeprecationWarning(message)
+    warnings.warn(message, category=PipDeprecationWarning, stacklevel=2)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/encoding.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/encoding.py
new file mode 100644
index 0000000..d36defa
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/encoding.py
@@ -0,0 +1,39 @@
+import codecs
+import locale
+import re
+import sys
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import List, Tuple, Text  # noqa: F401
+
+BOMS = [
+    (codecs.BOM_UTF8, 'utf8'),
+    (codecs.BOM_UTF16, 'utf16'),
+    (codecs.BOM_UTF16_BE, 'utf16-be'),
+    (codecs.BOM_UTF16_LE, 'utf16-le'),
+    (codecs.BOM_UTF32, 'utf32'),
+    (codecs.BOM_UTF32_BE, 'utf32-be'),
+    (codecs.BOM_UTF32_LE, 'utf32-le'),
+]  # type: List[Tuple[bytes, Text]]
+
+ENCODING_RE = re.compile(br'coding[:=]\s*([-\w.]+)')
+
+
+def auto_decode(data):
+    # type: (bytes) -> Text
+    """Check a bytes string for a BOM to correctly detect the encoding
+
+    Fallback to locale.getpreferredencoding(False) like open() on Python3"""
+    for bom, encoding in BOMS:
+        if data.startswith(bom):
+            return data[len(bom):].decode(encoding)
+    # Lets check the first two lines as in PEP263
+    for line in data.split(b'\n')[:2]:
+        if line[0:1] == b'#' and ENCODING_RE.search(line):
+            encoding = ENCODING_RE.search(line).groups()[0].decode('ascii')
+            return data.decode(encoding)
+    return data.decode(
+        locale.getpreferredencoding(False) or sys.getdefaultencoding(),
+    )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/filesystem.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/filesystem.py
new file mode 100644
index 0000000..1e6b033
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/filesystem.py
@@ -0,0 +1,30 @@
+import os
+import os.path
+
+from pip._internal.utils.compat import get_path_uid
+
+
+def check_path_owner(path):
+    # type: (str) -> bool
+    # If we don't have a way to check the effective uid of this process, then
+    # we'll just assume that we own the directory.
+    if not hasattr(os, "geteuid"):
+        return True
+
+    previous = None
+    while path != previous:
+        if os.path.lexists(path):
+            # Check if path is writable by current user.
+            if os.geteuid() == 0:
+                # Special handling for root user in order to handle properly
+                # cases where users use sudo without -H flag.
+                try:
+                    path_uid = get_path_uid(path)
+                except OSError:
+                    return False
+                return path_uid == 0
+            else:
+                return os.access(path, os.W_OK)
+        else:
+            previous, path = path, os.path.dirname(path)
+    return False  # assume we don't own the path
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/glibc.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/glibc.py
new file mode 100644
index 0000000..8a51f69
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/glibc.py
@@ -0,0 +1,93 @@
+from __future__ import absolute_import
+
+import ctypes
+import re
+import warnings
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Tuple  # noqa: F401
+
+
+def glibc_version_string():
+    # type: () -> Optional[str]
+    "Returns glibc version string, or None if not using glibc."
+
+    # ctypes.CDLL(None) internally calls dlopen(NULL), and as the dlopen
+    # manpage says, "If filename is NULL, then the returned handle is for the
+    # main program". This way we can let the linker do the work to figure out
+    # which libc our process is actually using.
+    process_namespace = ctypes.CDLL(None)
+    try:
+        gnu_get_libc_version = process_namespace.gnu_get_libc_version
+    except AttributeError:
+        # Symbol doesn't exist -> therefore, we are not linked to
+        # glibc.
+        return None
+
+    # Call gnu_get_libc_version, which returns a string like "2.5"
+    gnu_get_libc_version.restype = ctypes.c_char_p
+    version_str = gnu_get_libc_version()
+    # py2 / py3 compatibility:
+    if not isinstance(version_str, str):
+        version_str = version_str.decode("ascii")
+
+    return version_str
+
+
+# Separated out from have_compatible_glibc for easier unit testing
+def check_glibc_version(version_str, required_major, minimum_minor):
+    # type: (str, int, int) -> bool
+    # Parse string and check against requested version.
+    #
+    # We use a regexp instead of str.split because we want to discard any
+    # random junk that might come after the minor version -- this might happen
+    # in patched/forked versions of glibc (e.g. Linaro's version of glibc
+    # uses version strings like "2.20-2014.11"). See gh-3588.
+    m = re.match(r"(?P<major>[0-9]+)\.(?P<minor>[0-9]+)", version_str)
+    if not m:
+        warnings.warn("Expected glibc version with 2 components major.minor,"
+                      " got: %s" % version_str, RuntimeWarning)
+        return False
+    return (int(m.group("major")) == required_major and
+            int(m.group("minor")) >= minimum_minor)
+
+
+def have_compatible_glibc(required_major, minimum_minor):
+    # type: (int, int) -> bool
+    version_str = glibc_version_string()  # type: Optional[str]
+    if version_str is None:
+        return False
+    return check_glibc_version(version_str, required_major, minimum_minor)
+
+
+# platform.libc_ver regularly returns completely nonsensical glibc
+# versions. E.g. on my computer, platform says:
+#
+#   ~$ python2.7 -c 'import platform; print(platform.libc_ver())'
+#   ('glibc', '2.7')
+#   ~$ python3.5 -c 'import platform; print(platform.libc_ver())'
+#   ('glibc', '2.9')
+#
+# But the truth is:
+#
+#   ~$ ldd --version
+#   ldd (Debian GLIBC 2.22-11) 2.22
+#
+# This is unfortunate, because it means that the linehaul data on libc
+# versions that was generated by pip 8.1.2 and earlier is useless and
+# misleading. Solution: instead of using platform, use our code that actually
+# works.
+def libc_ver():
+    # type: () -> Tuple[str, str]
+    """Try to determine the glibc version
+
+    Returns a tuple of strings (lib, version) which default to empty strings
+    in case the lookup fails.
+    """
+    glibc_version = glibc_version_string()
+    if glibc_version is None:
+        return ("", "")
+    else:
+        return ("glibc", glibc_version)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/hashes.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/hashes.py
new file mode 100644
index 0000000..c6df7a1
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/hashes.py
@@ -0,0 +1,115 @@
+from __future__ import absolute_import
+
+import hashlib
+
+from pip._vendor.six import iteritems, iterkeys, itervalues
+
+from pip._internal.exceptions import (
+    HashMismatch, HashMissing, InstallationError,
+)
+from pip._internal.utils.misc import read_chunks
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Dict, List, BinaryIO, NoReturn, Iterator
+    )
+    from pip._vendor.six import PY3
+    if PY3:
+        from hashlib import _Hash  # noqa: F401
+    else:
+        from hashlib import _hash as _Hash  # noqa: F401
+
+
+# The recommended hash algo of the moment. Change this whenever the state of
+# the art changes; it won't hurt backward compatibility.
+FAVORITE_HASH = 'sha256'
+
+
+# Names of hashlib algorithms allowed by the --hash option and ``pip hash``
+# Currently, those are the ones at least as collision-resistant as sha256.
+STRONG_HASHES = ['sha256', 'sha384', 'sha512']
+
+
+class Hashes(object):
+    """A wrapper that builds multiple hashes at once and checks them against
+    known-good values
+
+    """
+    def __init__(self, hashes=None):
+        # type: (Dict[str, List[str]]) -> None
+        """
+        :param hashes: A dict of algorithm names pointing to lists of allowed
+            hex digests
+        """
+        self._allowed = {} if hashes is None else hashes
+
+    def check_against_chunks(self, chunks):
+        # type: (Iterator[bytes]) -> None
+        """Check good hashes against ones built from iterable of chunks of
+        data.
+
+        Raise HashMismatch if none match.
+
+        """
+        gots = {}
+        for hash_name in iterkeys(self._allowed):
+            try:
+                gots[hash_name] = hashlib.new(hash_name)
+            except (ValueError, TypeError):
+                raise InstallationError('Unknown hash name: %s' % hash_name)
+
+        for chunk in chunks:
+            for hash in itervalues(gots):
+                hash.update(chunk)
+
+        for hash_name, got in iteritems(gots):
+            if got.hexdigest() in self._allowed[hash_name]:
+                return
+        self._raise(gots)
+
+    def _raise(self, gots):
+        # type: (Dict[str, _Hash]) -> NoReturn
+        raise HashMismatch(self._allowed, gots)
+
+    def check_against_file(self, file):
+        # type: (BinaryIO) -> None
+        """Check good hashes against a file-like object
+
+        Raise HashMismatch if none match.
+
+        """
+        return self.check_against_chunks(read_chunks(file))
+
+    def check_against_path(self, path):
+        # type: (str) -> None
+        with open(path, 'rb') as file:
+            return self.check_against_file(file)
+
+    def __nonzero__(self):
+        # type: () -> bool
+        """Return whether I know any known-good hashes."""
+        return bool(self._allowed)
+
+    def __bool__(self):
+        # type: () -> bool
+        return self.__nonzero__()
+
+
+class MissingHashes(Hashes):
+    """A workalike for Hashes used when we're missing a hash for a requirement
+
+    It computes the actual hash of the requirement and raises a HashMissing
+    exception showing it to the user.
+
+    """
+    def __init__(self):
+        # type: () -> None
+        """Don't offer the ``hashes`` kwarg."""
+        # Pass our favorite hash in to generate a "gotten hash". With the
+        # empty list, it will never match, so an error will always raise.
+        super(MissingHashes, self).__init__(hashes={FAVORITE_HASH: []})
+
+    def _raise(self, gots):
+        # type: (Dict[str, _Hash]) -> NoReturn
+        raise HashMissing(gots[FAVORITE_HASH].hexdigest())
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/logging.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/logging.py
new file mode 100644
index 0000000..579d696
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/logging.py
@@ -0,0 +1,318 @@
+from __future__ import absolute_import
+
+import contextlib
+import errno
+import logging
+import logging.handlers
+import os
+import sys
+
+from pip._vendor.six import PY2
+
+from pip._internal.utils.compat import WINDOWS
+from pip._internal.utils.misc import ensure_dir
+
+try:
+    import threading
+except ImportError:
+    import dummy_threading as threading  # type: ignore
+
+
+try:
+    from pip._vendor import colorama
+# Lots of different errors can come from this, including SystemError and
+# ImportError.
+except Exception:
+    colorama = None
+
+
+_log_state = threading.local()
+_log_state.indentation = 0
+
+
+class BrokenStdoutLoggingError(Exception):
+    """
+    Raised if BrokenPipeError occurs for the stdout stream while logging.
+    """
+    pass
+
+
+# BrokenPipeError does not exist in Python 2 and, in addition, manifests
+# differently in Windows and non-Windows.
+if WINDOWS:
+    # In Windows, a broken pipe can show up as EINVAL rather than EPIPE:
+    # https://bugs.python.org/issue19612
+    # https://bugs.python.org/issue30418
+    if PY2:
+        def _is_broken_pipe_error(exc_class, exc):
+            """See the docstring for non-Windows Python 3 below."""
+            return (exc_class is IOError and
+                    exc.errno in (errno.EINVAL, errno.EPIPE))
+    else:
+        # In Windows, a broken pipe IOError became OSError in Python 3.
+        def _is_broken_pipe_error(exc_class, exc):
+            """See the docstring for non-Windows Python 3 below."""
+            return ((exc_class is BrokenPipeError) or  # noqa: F821
+                    (exc_class is OSError and
+                     exc.errno in (errno.EINVAL, errno.EPIPE)))
+elif PY2:
+    def _is_broken_pipe_error(exc_class, exc):
+        """See the docstring for non-Windows Python 3 below."""
+        return (exc_class is IOError and exc.errno == errno.EPIPE)
+else:
+    # Then we are in the non-Windows Python 3 case.
+    def _is_broken_pipe_error(exc_class, exc):
+        """
+        Return whether an exception is a broken pipe error.
+
+        Args:
+          exc_class: an exception class.
+          exc: an exception instance.
+        """
+        return (exc_class is BrokenPipeError)  # noqa: F821
+
+
+@contextlib.contextmanager
+def indent_log(num=2):
+    """
+    A context manager which will cause the log output to be indented for any
+    log messages emitted inside it.
+    """
+    _log_state.indentation += num
+    try:
+        yield
+    finally:
+        _log_state.indentation -= num
+
+
+def get_indentation():
+    return getattr(_log_state, 'indentation', 0)
+
+
+class IndentingFormatter(logging.Formatter):
+    def __init__(self, *args, **kwargs):
+        """
+        A logging.Formatter obeying containing indent_log contexts.
+
+        :param add_timestamp: A bool indicating output lines should be prefixed
+            with their record's timestamp.
+        """
+        self.add_timestamp = kwargs.pop("add_timestamp", False)
+        super(IndentingFormatter, self).__init__(*args, **kwargs)
+
+    def format(self, record):
+        """
+        Calls the standard formatter, but will indent all of the log messages
+        by our current indentation level.
+        """
+        formatted = super(IndentingFormatter, self).format(record)
+        prefix = ''
+        if self.add_timestamp:
+            prefix = self.formatTime(record, "%Y-%m-%dT%H:%M:%S ")
+        prefix += " " * get_indentation()
+        formatted = "".join([
+            prefix + line
+            for line in formatted.splitlines(True)
+        ])
+        return formatted
+
+
+def _color_wrap(*colors):
+    def wrapped(inp):
+        return "".join(list(colors) + [inp, colorama.Style.RESET_ALL])
+    return wrapped
+
+
+class ColorizedStreamHandler(logging.StreamHandler):
+
+    # Don't build up a list of colors if we don't have colorama
+    if colorama:
+        COLORS = [
+            # This needs to be in order from highest logging level to lowest.
+            (logging.ERROR, _color_wrap(colorama.Fore.RED)),
+            (logging.WARNING, _color_wrap(colorama.Fore.YELLOW)),
+        ]
+    else:
+        COLORS = []
+
+    def __init__(self, stream=None, no_color=None):
+        logging.StreamHandler.__init__(self, stream)
+        self._no_color = no_color
+
+        if WINDOWS and colorama:
+            self.stream = colorama.AnsiToWin32(self.stream)
+
+    def _using_stdout(self):
+        """
+        Return whether the handler is using sys.stdout.
+        """
+        if WINDOWS and colorama:
+            # Then self.stream is an AnsiToWin32 object.
+            return self.stream.wrapped is sys.stdout
+
+        return self.stream is sys.stdout
+
+    def should_color(self):
+        # Don't colorize things if we do not have colorama or if told not to
+        if not colorama or self._no_color:
+            return False
+
+        real_stream = (
+            self.stream if not isinstance(self.stream, colorama.AnsiToWin32)
+            else self.stream.wrapped
+        )
+
+        # If the stream is a tty we should color it
+        if hasattr(real_stream, "isatty") and real_stream.isatty():
+            return True
+
+        # If we have an ANSI term we should color it
+        if os.environ.get("TERM") == "ANSI":
+            return True
+
+        # If anything else we should not color it
+        return False
+
+    def format(self, record):
+        msg = logging.StreamHandler.format(self, record)
+
+        if self.should_color():
+            for level, color in self.COLORS:
+                if record.levelno >= level:
+                    msg = color(msg)
+                    break
+
+        return msg
+
+    # The logging module says handleError() can be customized.
+    def handleError(self, record):
+        exc_class, exc = sys.exc_info()[:2]
+        # If a broken pipe occurred while calling write() or flush() on the
+        # stdout stream in logging's Handler.emit(), then raise our special
+        # exception so we can handle it in main() instead of logging the
+        # broken pipe error and continuing.
+        if (exc_class and self._using_stdout() and
+                _is_broken_pipe_error(exc_class, exc)):
+            raise BrokenStdoutLoggingError()
+
+        return super(ColorizedStreamHandler, self).handleError(record)
+
+
+class BetterRotatingFileHandler(logging.handlers.RotatingFileHandler):
+
+    def _open(self):
+        ensure_dir(os.path.dirname(self.baseFilename))
+        return logging.handlers.RotatingFileHandler._open(self)
+
+
+class MaxLevelFilter(logging.Filter):
+
+    def __init__(self, level):
+        self.level = level
+
+    def filter(self, record):
+        return record.levelno < self.level
+
+
+def setup_logging(verbosity, no_color, user_log_file):
+    """Configures and sets up all of the logging
+
+    Returns the requested logging level, as its integer value.
+    """
+
+    # Determine the level to be logging at.
+    if verbosity >= 1:
+        level = "DEBUG"
+    elif verbosity == -1:
+        level = "WARNING"
+    elif verbosity == -2:
+        level = "ERROR"
+    elif verbosity <= -3:
+        level = "CRITICAL"
+    else:
+        level = "INFO"
+
+    level_number = getattr(logging, level)
+
+    # The "root" logger should match the "console" level *unless* we also need
+    # to log to a user log file.
+    include_user_log = user_log_file is not None
+    if include_user_log:
+        additional_log_file = user_log_file
+        root_level = "DEBUG"
+    else:
+        additional_log_file = "/dev/null"
+        root_level = level
+
+    # Disable any logging besides WARNING unless we have DEBUG level logging
+    # enabled for vendored libraries.
+    vendored_log_level = "WARNING" if level in ["INFO", "ERROR"] else "DEBUG"
+
+    # Shorthands for clarity
+    log_streams = {
+        "stdout": "ext://sys.stdout",
+        "stderr": "ext://sys.stderr",
+    }
+    handler_classes = {
+        "stream": "pip._internal.utils.logging.ColorizedStreamHandler",
+        "file": "pip._internal.utils.logging.BetterRotatingFileHandler",
+    }
+
+    logging.config.dictConfig({
+        "version": 1,
+        "disable_existing_loggers": False,
+        "filters": {
+            "exclude_warnings": {
+                "()": "pip._internal.utils.logging.MaxLevelFilter",
+                "level": logging.WARNING,
+            },
+        },
+        "formatters": {
+            "indent": {
+                "()": IndentingFormatter,
+                "format": "%(message)s",
+            },
+            "indent_with_timestamp": {
+                "()": IndentingFormatter,
+                "format": "%(message)s",
+                "add_timestamp": True,
+            },
+        },
+        "handlers": {
+            "console": {
+                "level": level,
+                "class": handler_classes["stream"],
+                "no_color": no_color,
+                "stream": log_streams["stdout"],
+                "filters": ["exclude_warnings"],
+                "formatter": "indent",
+            },
+            "console_errors": {
+                "level": "WARNING",
+                "class": handler_classes["stream"],
+                "no_color": no_color,
+                "stream": log_streams["stderr"],
+                "formatter": "indent",
+            },
+            "user_log": {
+                "level": "DEBUG",
+                "class": handler_classes["file"],
+                "filename": additional_log_file,
+                "delay": True,
+                "formatter": "indent_with_timestamp",
+            },
+        },
+        "root": {
+            "level": root_level,
+            "handlers": ["console", "console_errors"] + (
+                ["user_log"] if include_user_log else []
+            ),
+        },
+        "loggers": {
+            "pip._vendor": {
+                "level": vendored_log_level
+            }
+        },
+    })
+
+    return level_number
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/misc.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/misc.py
new file mode 100644
index 0000000..84605ee
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/misc.py
@@ -0,0 +1,1040 @@
+from __future__ import absolute_import
+
+import contextlib
+import errno
+import io
+import locale
+# we have a submodule named 'logging' which would shadow this if we used the
+# regular name:
+import logging as std_logging
+import os
+import posixpath
+import re
+import shutil
+import stat
+import subprocess
+import sys
+import tarfile
+import zipfile
+from collections import deque
+
+from pip._vendor import pkg_resources
+# NOTE: retrying is not annotated in typeshed as on 2017-07-17, which is
+#       why we ignore the type on this import.
+from pip._vendor.retrying import retry  # type: ignore
+from pip._vendor.six import PY2
+from pip._vendor.six.moves import input
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+from pip._vendor.six.moves.urllib.parse import unquote as urllib_unquote
+
+from pip._internal.exceptions import CommandError, InstallationError
+from pip._internal.locations import (
+    running_under_virtualenv, site_packages, user_site, virtualenv_no_global,
+    write_delete_marker_file,
+)
+from pip._internal.utils.compat import (
+    WINDOWS, console_to_str, expanduser, stdlib_pkgs,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if PY2:
+    from io import BytesIO as StringIO
+else:
+    from io import StringIO
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Optional, Tuple, Iterable, List, Match, Union, Any, Mapping, Text,
+        AnyStr, Container
+    )
+    from pip._vendor.pkg_resources import Distribution  # noqa: F401
+    from pip._internal.models.link import Link  # noqa: F401
+    from pip._internal.utils.ui import SpinnerInterface  # noqa: F401
+
+
+__all__ = ['rmtree', 'display_path', 'backup_dir',
+           'ask', 'splitext',
+           'format_size', 'is_installable_dir',
+           'is_svn_page', 'file_contents',
+           'split_leading_dir', 'has_leading_dir',
+           'normalize_path',
+           'renames', 'get_prog',
+           'unzip_file', 'untar_file', 'unpack_file', 'call_subprocess',
+           'captured_stdout', 'ensure_dir',
+           'ARCHIVE_EXTENSIONS', 'SUPPORTED_EXTENSIONS', 'WHEEL_EXTENSION',
+           'get_installed_version', 'remove_auth_from_url']
+
+
+logger = std_logging.getLogger(__name__)
+
+WHEEL_EXTENSION = '.whl'
+BZ2_EXTENSIONS = ('.tar.bz2', '.tbz')
+XZ_EXTENSIONS = ('.tar.xz', '.txz', '.tlz', '.tar.lz', '.tar.lzma')
+ZIP_EXTENSIONS = ('.zip', WHEEL_EXTENSION)
+TAR_EXTENSIONS = ('.tar.gz', '.tgz', '.tar')
+ARCHIVE_EXTENSIONS = (
+    ZIP_EXTENSIONS + BZ2_EXTENSIONS + TAR_EXTENSIONS + XZ_EXTENSIONS)
+SUPPORTED_EXTENSIONS = ZIP_EXTENSIONS + TAR_EXTENSIONS
+
+try:
+    import bz2  # noqa
+    SUPPORTED_EXTENSIONS += BZ2_EXTENSIONS
+except ImportError:
+    logger.debug('bz2 module is not available')
+
+try:
+    # Only for Python 3.3+
+    import lzma  # noqa
+    SUPPORTED_EXTENSIONS += XZ_EXTENSIONS
+except ImportError:
+    logger.debug('lzma module is not available')
+
+
+def ensure_dir(path):
+    # type: (AnyStr) -> None
+    """os.path.makedirs without EEXIST."""
+    try:
+        os.makedirs(path)
+    except OSError as e:
+        if e.errno != errno.EEXIST:
+            raise
+
+
+def get_prog():
+    # type: () -> str
+    try:
+        prog = os.path.basename(sys.argv[0])
+        if prog in ('__main__.py', '-c'):
+            return "%s -m pip" % sys.executable
+        else:
+            return prog
+    except (AttributeError, TypeError, IndexError):
+        pass
+    return 'pip'
+
+
+# Retry every half second for up to 3 seconds
+@retry(stop_max_delay=3000, wait_fixed=500)
+def rmtree(dir, ignore_errors=False):
+    # type: (str, bool) -> None
+    shutil.rmtree(dir, ignore_errors=ignore_errors,
+                  onerror=rmtree_errorhandler)
+
+
+def rmtree_errorhandler(func, path, exc_info):
+    """On Windows, the files in .svn are read-only, so when rmtree() tries to
+    remove them, an exception is thrown.  We catch that here, remove the
+    read-only attribute, and hopefully continue without problems."""
+    # if file type currently read only
+    if os.stat(path).st_mode & stat.S_IREAD:
+        # convert to read/write
+        os.chmod(path, stat.S_IWRITE)
+        # use the original function to repeat the operation
+        func(path)
+        return
+    else:
+        raise
+
+
+def display_path(path):
+    # type: (Union[str, Text]) -> str
+    """Gives the display value for a given path, making it relative to cwd
+    if possible."""
+    path = os.path.normcase(os.path.abspath(path))
+    if sys.version_info[0] == 2:
+        path = path.decode(sys.getfilesystemencoding(), 'replace')
+        path = path.encode(sys.getdefaultencoding(), 'replace')
+    if path.startswith(os.getcwd() + os.path.sep):
+        path = '.' + path[len(os.getcwd()):]
+    return path
+
+
+def backup_dir(dir, ext='.bak'):
+    # type: (str, str) -> str
+    """Figure out the name of a directory to back up the given dir to
+    (adding .bak, .bak2, etc)"""
+    n = 1
+    extension = ext
+    while os.path.exists(dir + extension):
+        n += 1
+        extension = ext + str(n)
+    return dir + extension
+
+
+def ask_path_exists(message, options):
+    # type: (str, Iterable[str]) -> str
+    for action in os.environ.get('PIP_EXISTS_ACTION', '').split():
+        if action in options:
+            return action
+    return ask(message, options)
+
+
+def ask(message, options):
+    # type: (str, Iterable[str]) -> str
+    """Ask the message interactively, with the given possible responses"""
+    while 1:
+        if os.environ.get('PIP_NO_INPUT'):
+            raise Exception(
+                'No input was expected ($PIP_NO_INPUT set); question: %s' %
+                message
+            )
+        response = input(message)
+        response = response.strip().lower()
+        if response not in options:
+            print(
+                'Your response (%r) was not one of the expected responses: '
+                '%s' % (response, ', '.join(options))
+            )
+        else:
+            return response
+
+
+def format_size(bytes):
+    # type: (float) -> str
+    if bytes > 1000 * 1000:
+        return '%.1fMB' % (bytes / 1000.0 / 1000)
+    elif bytes > 10 * 1000:
+        return '%ikB' % (bytes / 1000)
+    elif bytes > 1000:
+        return '%.1fkB' % (bytes / 1000.0)
+    else:
+        return '%ibytes' % bytes
+
+
+def is_installable_dir(path):
+    # type: (str) -> bool
+    """Is path is a directory containing setup.py or pyproject.toml?
+    """
+    if not os.path.isdir(path):
+        return False
+    setup_py = os.path.join(path, 'setup.py')
+    if os.path.isfile(setup_py):
+        return True
+    pyproject_toml = os.path.join(path, 'pyproject.toml')
+    if os.path.isfile(pyproject_toml):
+        return True
+    return False
+
+
+def is_svn_page(html):
+    # type: (Union[str, Text]) -> Optional[Match[Union[str, Text]]]
+    """
+    Returns true if the page appears to be the index page of an svn repository
+    """
+    return (re.search(r'<title>[^<]*Revision \d+:', html) and
+            re.search(r'Powered by (?:<a[^>]*?>)?Subversion', html, re.I))
+
+
+def file_contents(filename):
+    # type: (str) -> Text
+    with open(filename, 'rb') as fp:
+        return fp.read().decode('utf-8')
+
+
+def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
+    """Yield pieces of data from a file-like object until EOF."""
+    while True:
+        chunk = file.read(size)
+        if not chunk:
+            break
+        yield chunk
+
+
+def split_leading_dir(path):
+    # type: (Union[str, Text]) -> List[Union[str, Text]]
+    path = path.lstrip('/').lstrip('\\')
+    if '/' in path and (('\\' in path and path.find('/') < path.find('\\')) or
+                        '\\' not in path):
+        return path.split('/', 1)
+    elif '\\' in path:
+        return path.split('\\', 1)
+    else:
+        return [path, '']
+
+
+def has_leading_dir(paths):
+    # type: (Iterable[Union[str, Text]]) -> bool
+    """Returns true if all the paths have the same leading path name
+    (i.e., everything is in one subdirectory in an archive)"""
+    common_prefix = None
+    for path in paths:
+        prefix, rest = split_leading_dir(path)
+        if not prefix:
+            return False
+        elif common_prefix is None:
+            common_prefix = prefix
+        elif prefix != common_prefix:
+            return False
+    return True
+
+
+def normalize_path(path, resolve_symlinks=True):
+    # type: (str, bool) -> str
+    """
+    Convert a path to its canonical, case-normalized, absolute version.
+
+    """
+    path = expanduser(path)
+    if resolve_symlinks:
+        path = os.path.realpath(path)
+    else:
+        path = os.path.abspath(path)
+    return os.path.normcase(path)
+
+
+def splitext(path):
+    # type: (str) -> Tuple[str, str]
+    """Like os.path.splitext, but take off .tar too"""
+    base, ext = posixpath.splitext(path)
+    if base.lower().endswith('.tar'):
+        ext = base[-4:] + ext
+        base = base[:-4]
+    return base, ext
+
+
+def renames(old, new):
+    # type: (str, str) -> None
+    """Like os.renames(), but handles renaming across devices."""
+    # Implementation borrowed from os.renames().
+    head, tail = os.path.split(new)
+    if head and tail and not os.path.exists(head):
+        os.makedirs(head)
+
+    shutil.move(old, new)
+
+    head, tail = os.path.split(old)
+    if head and tail:
+        try:
+            os.removedirs(head)
+        except OSError:
+            pass
+
+
+def is_local(path):
+    # type: (str) -> bool
+    """
+    Return True if path is within sys.prefix, if we're running in a virtualenv.
+
+    If we're not in a virtualenv, all paths are considered "local."
+
+    """
+    if not running_under_virtualenv():
+        return True
+    return normalize_path(path).startswith(normalize_path(sys.prefix))
+
+
+def dist_is_local(dist):
+    # type: (Distribution) -> bool
+    """
+    Return True if given Distribution object is installed locally
+    (i.e. within current virtualenv).
+
+    Always True if we're not in a virtualenv.
+
+    """
+    return is_local(dist_location(dist))
+
+
+def dist_in_usersite(dist):
+    # type: (Distribution) -> bool
+    """
+    Return True if given Distribution is installed in user site.
+    """
+    norm_path = normalize_path(dist_location(dist))
+    return norm_path.startswith(normalize_path(user_site))
+
+
+def dist_in_site_packages(dist):
+    # type: (Distribution) -> bool
+    """
+    Return True if given Distribution is installed in
+    sysconfig.get_python_lib().
+    """
+    return normalize_path(
+        dist_location(dist)
+    ).startswith(normalize_path(site_packages))
+
+
+def dist_is_editable(dist):
+    # type: (Distribution) -> bool
+    """
+    Return True if given Distribution is an editable install.
+    """
+    for path_item in sys.path:
+        egg_link = os.path.join(path_item, dist.project_name + '.egg-link')
+        if os.path.isfile(egg_link):
+            return True
+    return False
+
+
+def get_installed_distributions(local_only=True,
+                                skip=stdlib_pkgs,
+                                include_editables=True,
+                                editables_only=False,
+                                user_only=False):
+    # type: (bool, Container[str], bool, bool, bool) -> List[Distribution]
+    """
+    Return a list of installed Distribution objects.
+
+    If ``local_only`` is True (default), only return installations
+    local to the current virtualenv, if in a virtualenv.
+
+    ``skip`` argument is an iterable of lower-case project names to
+    ignore; defaults to stdlib_pkgs
+
+    If ``include_editables`` is False, don't report editables.
+
+    If ``editables_only`` is True , only report editables.
+
+    If ``user_only`` is True , only report installations in the user
+    site directory.
+
+    """
+    if local_only:
+        local_test = dist_is_local
+    else:
+        def local_test(d):
+            return True
+
+    if include_editables:
+        def editable_test(d):
+            return True
+    else:
+        def editable_test(d):
+            return not dist_is_editable(d)
+
+    if editables_only:
+        def editables_only_test(d):
+            return dist_is_editable(d)
+    else:
+        def editables_only_test(d):
+            return True
+
+    if user_only:
+        user_test = dist_in_usersite
+    else:
+        def user_test(d):
+            return True
+
+    # because of pkg_resources vendoring, mypy cannot find stub in typeshed
+    return [d for d in pkg_resources.working_set  # type: ignore
+            if local_test(d) and
+            d.key not in skip and
+            editable_test(d) and
+            editables_only_test(d) and
+            user_test(d)
+            ]
+
+
+def egg_link_path(dist):
+    # type: (Distribution) -> Optional[str]
+    """
+    Return the path for the .egg-link file if it exists, otherwise, None.
+
+    There's 3 scenarios:
+    1) not in a virtualenv
+       try to find in site.USER_SITE, then site_packages
+    2) in a no-global virtualenv
+       try to find in site_packages
+    3) in a yes-global virtualenv
+       try to find in site_packages, then site.USER_SITE
+       (don't look in global location)
+
+    For #1 and #3, there could be odd cases, where there's an egg-link in 2
+    locations.
+
+    This method will just return the first one found.
+    """
+    sites = []
+    if running_under_virtualenv():
+        if virtualenv_no_global():
+            sites.append(site_packages)
+        else:
+            sites.append(site_packages)
+            if user_site:
+                sites.append(user_site)
+    else:
+        if user_site:
+            sites.append(user_site)
+        sites.append(site_packages)
+
+    for site in sites:
+        egglink = os.path.join(site, dist.project_name) + '.egg-link'
+        if os.path.isfile(egglink):
+            return egglink
+    return None
+
+
+def dist_location(dist):
+    # type: (Distribution) -> str
+    """
+    Get the site-packages location of this distribution. Generally
+    this is dist.location, except in the case of develop-installed
+    packages, where dist.location is the source code location, and we
+    want to know where the egg-link file is.
+
+    """
+    egg_link = egg_link_path(dist)
+    if egg_link:
+        return egg_link
+    return dist.location
+
+
+def current_umask():
+    """Get the current umask which involves having to set it temporarily."""
+    mask = os.umask(0)
+    os.umask(mask)
+    return mask
+
+
+def unzip_file(filename, location, flatten=True):
+    # type: (str, str, bool) -> None
+    """
+    Unzip the file (with path `filename`) to the destination `location`.  All
+    files are written based on system defaults and umask (i.e. permissions are
+    not preserved), except that regular file members with any execute
+    permissions (user, group, or world) have "chmod +x" applied after being
+    written. Note that for windows, any execute changes using os.chmod are
+    no-ops per the python docs.
+    """
+    ensure_dir(location)
+    zipfp = open(filename, 'rb')
+    try:
+        zip = zipfile.ZipFile(zipfp, allowZip64=True)
+        leading = has_leading_dir(zip.namelist()) and flatten
+        for info in zip.infolist():
+            name = info.filename
+            fn = name
+            if leading:
+                fn = split_leading_dir(name)[1]
+            fn = os.path.join(location, fn)
+            dir = os.path.dirname(fn)
+            if fn.endswith('/') or fn.endswith('\\'):
+                # A directory
+                ensure_dir(fn)
+            else:
+                ensure_dir(dir)
+                # Don't use read() to avoid allocating an arbitrarily large
+                # chunk of memory for the file's content
+                fp = zip.open(name)
+                try:
+                    with open(fn, 'wb') as destfp:
+                        shutil.copyfileobj(fp, destfp)
+                finally:
+                    fp.close()
+                    mode = info.external_attr >> 16
+                    # if mode and regular file and any execute permissions for
+                    # user/group/world?
+                    if mode and stat.S_ISREG(mode) and mode & 0o111:
+                        # make dest file have execute for user/group/world
+                        # (chmod +x) no-op on windows per python docs
+                        os.chmod(fn, (0o777 - current_umask() | 0o111))
+    finally:
+        zipfp.close()
+
+
+def untar_file(filename, location):
+    # type: (str, str) -> None
+    """
+    Untar the file (with path `filename`) to the destination `location`.
+    All files are written based on system defaults and umask (i.e. permissions
+    are not preserved), except that regular file members with any execute
+    permissions (user, group, or world) have "chmod +x" applied after being
+    written.  Note that for windows, any execute changes using os.chmod are
+    no-ops per the python docs.
+    """
+    ensure_dir(location)
+    if filename.lower().endswith('.gz') or filename.lower().endswith('.tgz'):
+        mode = 'r:gz'
+    elif filename.lower().endswith(BZ2_EXTENSIONS):
+        mode = 'r:bz2'
+    elif filename.lower().endswith(XZ_EXTENSIONS):
+        mode = 'r:xz'
+    elif filename.lower().endswith('.tar'):
+        mode = 'r'
+    else:
+        logger.warning(
+            'Cannot determine compression type for file %s', filename,
+        )
+        mode = 'r:*'
+    tar = tarfile.open(filename, mode)
+    try:
+        leading = has_leading_dir([
+            member.name for member in tar.getmembers()
+        ])
+        for member in tar.getmembers():
+            fn = member.name
+            if leading:
+                # https://github.com/python/mypy/issues/1174
+                fn = split_leading_dir(fn)[1]  # type: ignore
+            path = os.path.join(location, fn)
+            if member.isdir():
+                ensure_dir(path)
+            elif member.issym():
+                try:
+                    # https://github.com/python/typeshed/issues/2673
+                    tar._extract_member(member, path)  # type: ignore
+                except Exception as exc:
+                    # Some corrupt tar files seem to produce this
+                    # (specifically bad symlinks)
+                    logger.warning(
+                        'In the tar file %s the member %s is invalid: %s',
+                        filename, member.name, exc,
+                    )
+                    continue
+            else:
+                try:
+                    fp = tar.extractfile(member)
+                except (KeyError, AttributeError) as exc:
+                    # Some corrupt tar files seem to produce this
+                    # (specifically bad symlinks)
+                    logger.warning(
+                        'In the tar file %s the member %s is invalid: %s',
+                        filename, member.name, exc,
+                    )
+                    continue
+                ensure_dir(os.path.dirname(path))
+                with open(path, 'wb') as destfp:
+                    shutil.copyfileobj(fp, destfp)
+                fp.close()
+                # Update the timestamp (useful for cython compiled files)
+                # https://github.com/python/typeshed/issues/2673
+                tar.utime(member, path)  # type: ignore
+                # member have any execute permissions for user/group/world?
+                if member.mode & 0o111:
+                    # make dest file have execute for user/group/world
+                    # no-op on windows per python docs
+                    os.chmod(path, (0o777 - current_umask() | 0o111))
+    finally:
+        tar.close()
+
+
+def unpack_file(
+    filename,  # type: str
+    location,  # type: str
+    content_type,  # type: Optional[str]
+    link  # type: Optional[Link]
+):
+    # type: (...) -> None
+    filename = os.path.realpath(filename)
+    if (content_type == 'application/zip' or
+            filename.lower().endswith(ZIP_EXTENSIONS) or
+            zipfile.is_zipfile(filename)):
+        unzip_file(
+            filename,
+            location,
+            flatten=not filename.endswith('.whl')
+        )
+    elif (content_type == 'application/x-gzip' or
+            tarfile.is_tarfile(filename) or
+            filename.lower().endswith(
+                TAR_EXTENSIONS + BZ2_EXTENSIONS + XZ_EXTENSIONS)):
+        untar_file(filename, location)
+    elif (content_type and content_type.startswith('text/html') and
+            is_svn_page(file_contents(filename))):
+        # We don't really care about this
+        from pip._internal.vcs.subversion import Subversion
+        Subversion('svn+' + link.url).unpack(location)
+    else:
+        # FIXME: handle?
+        # FIXME: magic signatures?
+        logger.critical(
+            'Cannot unpack file %s (downloaded from %s, content-type: %s); '
+            'cannot detect archive format',
+            filename, location, content_type,
+        )
+        raise InstallationError(
+            'Cannot determine archive format of %s' % location
+        )
+
+
+def call_subprocess(
+    cmd,  # type: List[str]
+    show_stdout=True,  # type: bool
+    cwd=None,  # type: Optional[str]
+    on_returncode='raise',  # type: str
+    extra_ok_returncodes=None,  # type: Optional[Iterable[int]]
+    command_desc=None,  # type: Optional[str]
+    extra_environ=None,  # type: Optional[Mapping[str, Any]]
+    unset_environ=None,  # type: Optional[Iterable[str]]
+    spinner=None  # type: Optional[SpinnerInterface]
+):
+    # type: (...) -> Optional[Text]
+    """
+    Args:
+      extra_ok_returncodes: an iterable of integer return codes that are
+        acceptable, in addition to 0. Defaults to None, which means [].
+      unset_environ: an iterable of environment variable names to unset
+        prior to calling subprocess.Popen().
+    """
+    if extra_ok_returncodes is None:
+        extra_ok_returncodes = []
+    if unset_environ is None:
+        unset_environ = []
+    # This function's handling of subprocess output is confusing and I
+    # previously broke it terribly, so as penance I will write a long comment
+    # explaining things.
+    #
+    # The obvious thing that affects output is the show_stdout=
+    # kwarg. show_stdout=True means, let the subprocess write directly to our
+    # stdout. Even though it is nominally the default, it is almost never used
+    # inside pip (and should not be used in new code without a very good
+    # reason); as of 2016-02-22 it is only used in a few places inside the VCS
+    # wrapper code. Ideally we should get rid of it entirely, because it
+    # creates a lot of complexity here for a rarely used feature.
+    #
+    # Most places in pip set show_stdout=False. What this means is:
+    # - We connect the child stdout to a pipe, which we read.
+    # - By default, we hide the output but show a spinner -- unless the
+    #   subprocess exits with an error, in which case we show the output.
+    # - If the --verbose option was passed (= loglevel is DEBUG), then we show
+    #   the output unconditionally. (But in this case we don't want to show
+    #   the output a second time if it turns out that there was an error.)
+    #
+    # stderr is always merged with stdout (even if show_stdout=True).
+    if show_stdout:
+        stdout = None
+    else:
+        stdout = subprocess.PIPE
+    if command_desc is None:
+        cmd_parts = []
+        for part in cmd:
+            if ' ' in part or '\n' in part or '"' in part or "'" in part:
+                part = '"%s"' % part.replace('"', '\\"')
+            cmd_parts.append(part)
+        command_desc = ' '.join(cmd_parts)
+    logger.debug("Running command %s", command_desc)
+    env = os.environ.copy()
+    if extra_environ:
+        env.update(extra_environ)
+    for name in unset_environ:
+        env.pop(name, None)
+    try:
+        proc = subprocess.Popen(
+            cmd, stderr=subprocess.STDOUT, stdin=subprocess.PIPE,
+            stdout=stdout, cwd=cwd, env=env,
+        )
+        proc.stdin.close()
+    except Exception as exc:
+        logger.critical(
+            "Error %s while executing command %s", exc, command_desc,
+        )
+        raise
+    all_output = []
+    if stdout is not None:
+        while True:
+            line = console_to_str(proc.stdout.readline())
+            if not line:
+                break
+            line = line.rstrip()
+            all_output.append(line + '\n')
+            if logger.getEffectiveLevel() <= std_logging.DEBUG:
+                # Show the line immediately
+                logger.debug(line)
+            else:
+                # Update the spinner
+                if spinner is not None:
+                    spinner.spin()
+    try:
+        proc.wait()
+    finally:
+        if proc.stdout:
+            proc.stdout.close()
+    if spinner is not None:
+        if proc.returncode:
+            spinner.finish("error")
+        else:
+            spinner.finish("done")
+    if proc.returncode and proc.returncode not in extra_ok_returncodes:
+        if on_returncode == 'raise':
+            if (logger.getEffectiveLevel() > std_logging.DEBUG and
+                    not show_stdout):
+                logger.info(
+                    'Complete output from command %s:', command_desc,
+                )
+                logger.info(
+                    ''.join(all_output) +
+                    '\n----------------------------------------'
+                )
+            raise InstallationError(
+                'Command "%s" failed with error code %s in %s'
+                % (command_desc, proc.returncode, cwd))
+        elif on_returncode == 'warn':
+            logger.warning(
+                'Command "%s" had error code %s in %s',
+                command_desc, proc.returncode, cwd,
+            )
+        elif on_returncode == 'ignore':
+            pass
+        else:
+            raise ValueError('Invalid value: on_returncode=%s' %
+                             repr(on_returncode))
+    if not show_stdout:
+        return ''.join(all_output)
+    return None
+
+
+def read_text_file(filename):
+    # type: (str) -> str
+    """Return the contents of *filename*.
+
+    Try to decode the file contents with utf-8, the preferred system encoding
+    (e.g., cp1252 on some Windows machines), and latin1, in that order.
+    Decoding a byte string with latin1 will never raise an error. In the worst
+    case, the returned string will contain some garbage characters.
+
+    """
+    with open(filename, 'rb') as fp:
+        data = fp.read()
+
+    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
+    for enc in encodings:
+        try:
+            # https://github.com/python/mypy/issues/1174
+            data = data.decode(enc)  # type: ignore
+        except UnicodeDecodeError:
+            continue
+        break
+
+    assert not isinstance(data, bytes)  # Latin1 should have worked.
+    return data
+
+
+def _make_build_dir(build_dir):
+    os.makedirs(build_dir)
+    write_delete_marker_file(build_dir)
+
+
+class FakeFile(object):
+    """Wrap a list of lines in an object with readline() to make
+    ConfigParser happy."""
+    def __init__(self, lines):
+        self._gen = (l for l in lines)
+
+    def readline(self):
+        try:
+            try:
+                return next(self._gen)
+            except NameError:
+                return self._gen.next()
+        except StopIteration:
+            return ''
+
+    def __iter__(self):
+        return self._gen
+
+
+class StreamWrapper(StringIO):
+
+    @classmethod
+    def from_stream(cls, orig_stream):
+        cls.orig_stream = orig_stream
+        return cls()
+
+    # compileall.compile_dir() needs stdout.encoding to print to stdout
+    @property
+    def encoding(self):
+        return self.orig_stream.encoding
+
+
+@contextlib.contextmanager
+def captured_output(stream_name):
+    """Return a context manager used by captured_stdout/stdin/stderr
+    that temporarily replaces the sys stream *stream_name* with a StringIO.
+
+    Taken from Lib/support/__init__.py in the CPython repo.
+    """
+    orig_stdout = getattr(sys, stream_name)
+    setattr(sys, stream_name, StreamWrapper.from_stream(orig_stdout))
+    try:
+        yield getattr(sys, stream_name)
+    finally:
+        setattr(sys, stream_name, orig_stdout)
+
+
+def captured_stdout():
+    """Capture the output of sys.stdout:
+
+       with captured_stdout() as stdout:
+           print('hello')
+       self.assertEqual(stdout.getvalue(), 'hello\n')
+
+    Taken from Lib/support/__init__.py in the CPython repo.
+    """
+    return captured_output('stdout')
+
+
+def captured_stderr():
+    """
+    See captured_stdout().
+    """
+    return captured_output('stderr')
+
+
+class cached_property(object):
+    """A property that is only computed once per instance and then replaces
+       itself with an ordinary attribute. Deleting the attribute resets the
+       property.
+
+       Source: https://github.com/bottlepy/bottle/blob/0.11.5/bottle.py#L175
+    """
+
+    def __init__(self, func):
+        self.__doc__ = getattr(func, '__doc__')
+        self.func = func
+
+    def __get__(self, obj, cls):
+        if obj is None:
+            # We're being accessed from the class itself, not from an object
+            return self
+        value = obj.__dict__[self.func.__name__] = self.func(obj)
+        return value
+
+
+def get_installed_version(dist_name, working_set=None):
+    """Get the installed version of dist_name avoiding pkg_resources cache"""
+    # Create a requirement that we'll look for inside of setuptools.
+    req = pkg_resources.Requirement.parse(dist_name)
+
+    if working_set is None:
+        # We want to avoid having this cached, so we need to construct a new
+        # working set each time.
+        working_set = pkg_resources.WorkingSet()
+
+    # Get the installed distribution from our working set
+    dist = working_set.find(req)
+
+    # Check to see if we got an installed distribution or not, if we did
+    # we want to return it's version.
+    return dist.version if dist else None
+
+
+def consume(iterator):
+    """Consume an iterable at C speed."""
+    deque(iterator, maxlen=0)
+
+
+# Simulates an enum
+def enum(*sequential, **named):
+    enums = dict(zip(sequential, range(len(sequential))), **named)
+    reverse = {value: key for key, value in enums.items()}
+    enums['reverse_mapping'] = reverse
+    return type('Enum', (), enums)
+
+
+def make_vcs_requirement_url(repo_url, rev, project_name, subdir=None):
+    """
+    Return the URL for a VCS requirement.
+
+    Args:
+      repo_url: the remote VCS url, with any needed VCS prefix (e.g. "git+").
+      project_name: the (unescaped) project name.
+    """
+    egg_project_name = pkg_resources.to_filename(project_name)
+    req = '{}@{}#egg={}'.format(repo_url, rev, egg_project_name)
+    if subdir:
+        req += '&subdirectory={}'.format(subdir)
+
+    return req
+
+
+def split_auth_from_netloc(netloc):
+    """
+    Parse out and remove the auth information from a netloc.
+
+    Returns: (netloc, (username, password)).
+    """
+    if '@' not in netloc:
+        return netloc, (None, None)
+
+    # Split from the right because that's how urllib.parse.urlsplit()
+    # behaves if more than one @ is present (which can be checked using
+    # the password attribute of urlsplit()'s return value).
+    auth, netloc = netloc.rsplit('@', 1)
+    if ':' in auth:
+        # Split from the left because that's how urllib.parse.urlsplit()
+        # behaves if more than one : is present (which again can be checked
+        # using the password attribute of the return value)
+        user_pass = auth.split(':', 1)
+    else:
+        user_pass = auth, None
+
+    user_pass = tuple(
+        None if x is None else urllib_unquote(x) for x in user_pass
+    )
+
+    return netloc, user_pass
+
+
+def redact_netloc(netloc):
+    # type: (str) -> str
+    """
+    Replace the password in a netloc with "****", if it exists.
+
+    For example, "user:pass@example.com" returns "user:****@example.com".
+    """
+    netloc, (user, password) = split_auth_from_netloc(netloc)
+    if user is None:
+        return netloc
+    password = '' if password is None else ':****'
+    return '{user}{password}@{netloc}'.format(user=urllib_parse.quote(user),
+                                              password=password,
+                                              netloc=netloc)
+
+
+def _transform_url(url, transform_netloc):
+    purl = urllib_parse.urlsplit(url)
+    netloc = transform_netloc(purl.netloc)
+    # stripped url
+    url_pieces = (
+        purl.scheme, netloc, purl.path, purl.query, purl.fragment
+    )
+    surl = urllib_parse.urlunsplit(url_pieces)
+    return surl
+
+
+def _get_netloc(netloc):
+    return split_auth_from_netloc(netloc)[0]
+
+
+def remove_auth_from_url(url):
+    # type: (str) -> str
+    # Return a copy of url with 'username:password@' removed.
+    # username/pass params are passed to subversion through flags
+    # and are not recognized in the url.
+    return _transform_url(url, _get_netloc)
+
+
+def redact_password_from_url(url):
+    # type: (str) -> str
+    """Replace the password in a given url with ****."""
+    return _transform_url(url, redact_netloc)
+
+
+def protect_pip_from_modification_on_windows(modifying_pip):
+    """Protection of pip.exe from modification on Windows
+
+    On Windows, any operation modifying pip should be run as:
+        python -m pip ...
+    """
+    pip_names = [
+        "pip.exe",
+        "pip{}.exe".format(sys.version_info[0]),
+        "pip{}.{}.exe".format(*sys.version_info[:2])
+    ]
+
+    # See https://github.com/pypa/pip/issues/1299 for more discussion
+    should_show_use_python_msg = (
+        modifying_pip and
+        WINDOWS and
+        os.path.basename(sys.argv[0]) in pip_names
+    )
+
+    if should_show_use_python_msg:
+        new_command = [
+            sys.executable, "-m", "pip"
+        ] + sys.argv[1:]
+        raise CommandError(
+            'To modify pip, please run the following command:\n{}'
+            .format(" ".join(new_command))
+        )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/models.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/models.py
new file mode 100644
index 0000000..d5cb80a
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/models.py
@@ -0,0 +1,40 @@
+"""Utilities for defining models
+"""
+
+import operator
+
+
+class KeyBasedCompareMixin(object):
+    """Provides comparision capabilities that is based on a key
+    """
+
+    def __init__(self, key, defining_class):
+        self._compare_key = key
+        self._defining_class = defining_class
+
+    def __hash__(self):
+        return hash(self._compare_key)
+
+    def __lt__(self, other):
+        return self._compare(other, operator.__lt__)
+
+    def __le__(self, other):
+        return self._compare(other, operator.__le__)
+
+    def __gt__(self, other):
+        return self._compare(other, operator.__gt__)
+
+    def __ge__(self, other):
+        return self._compare(other, operator.__ge__)
+
+    def __eq__(self, other):
+        return self._compare(other, operator.__eq__)
+
+    def __ne__(self, other):
+        return self._compare(other, operator.__ne__)
+
+    def _compare(self, other, method):
+        if not isinstance(other, self._defining_class):
+            return NotImplemented
+
+        return method(self._compare_key, other._compare_key)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/outdated.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/outdated.py
new file mode 100644
index 0000000..37c47a4
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/outdated.py
@@ -0,0 +1,164 @@
+from __future__ import absolute_import
+
+import datetime
+import json
+import logging
+import os.path
+import sys
+
+from pip._vendor import lockfile, pkg_resources
+from pip._vendor.packaging import version as packaging_version
+
+from pip._internal.index import PackageFinder
+from pip._internal.utils.compat import WINDOWS
+from pip._internal.utils.filesystem import check_path_owner
+from pip._internal.utils.misc import ensure_dir, get_installed_version
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    import optparse  # noqa: F401
+    from typing import Any, Dict  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+
+
+SELFCHECK_DATE_FMT = "%Y-%m-%dT%H:%M:%SZ"
+
+
+logger = logging.getLogger(__name__)
+
+
+class SelfCheckState(object):
+    def __init__(self, cache_dir):
+        # type: (str) -> None
+        self.state = {}  # type: Dict[str, Any]
+        self.statefile_path = None
+
+        # Try to load the existing state
+        if cache_dir:
+            self.statefile_path = os.path.join(cache_dir, "selfcheck.json")
+            try:
+                with open(self.statefile_path) as statefile:
+                    self.state = json.load(statefile)[sys.prefix]
+            except (IOError, ValueError, KeyError):
+                # Explicitly suppressing exceptions, since we don't want to
+                # error out if the cache file is invalid.
+                pass
+
+    def save(self, pypi_version, current_time):
+        # type: (str, datetime.datetime) -> None
+        # If we do not have a path to cache in, don't bother saving.
+        if not self.statefile_path:
+            return
+
+        # Check to make sure that we own the directory
+        if not check_path_owner(os.path.dirname(self.statefile_path)):
+            return
+
+        # Now that we've ensured the directory is owned by this user, we'll go
+        # ahead and make sure that all our directories are created.
+        ensure_dir(os.path.dirname(self.statefile_path))
+
+        # Attempt to write out our version check file
+        with lockfile.LockFile(self.statefile_path):
+            if os.path.exists(self.statefile_path):
+                with open(self.statefile_path) as statefile:
+                    state = json.load(statefile)
+            else:
+                state = {}
+
+            state[sys.prefix] = {
+                "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
+                "pypi_version": pypi_version,
+            }
+
+            with open(self.statefile_path, "w") as statefile:
+                json.dump(state, statefile, sort_keys=True,
+                          separators=(",", ":"))
+
+
+def was_installed_by_pip(pkg):
+    # type: (str) -> bool
+    """Checks whether pkg was installed by pip
+
+    This is used not to display the upgrade message when pip is in fact
+    installed by system package manager, such as dnf on Fedora.
+    """
+    try:
+        dist = pkg_resources.get_distribution(pkg)
+        return (dist.has_metadata('INSTALLER') and
+                'pip' in dist.get_metadata_lines('INSTALLER'))
+    except pkg_resources.DistributionNotFound:
+        return False
+
+
+def pip_version_check(session, options):
+    # type: (PipSession, optparse.Values) -> None
+    """Check for an update for pip.
+
+    Limit the frequency of checks to once per week. State is stored either in
+    the active virtualenv or in the user's USER_CACHE_DIR keyed off the prefix
+    of the pip script path.
+    """
+    installed_version = get_installed_version("pip")
+    if not installed_version:
+        return
+
+    pip_version = packaging_version.parse(installed_version)
+    pypi_version = None
+
+    try:
+        state = SelfCheckState(cache_dir=options.cache_dir)
+
+        current_time = datetime.datetime.utcnow()
+        # Determine if we need to refresh the state
+        if "last_check" in state.state and "pypi_version" in state.state:
+            last_check = datetime.datetime.strptime(
+                state.state["last_check"],
+                SELFCHECK_DATE_FMT
+            )
+            if (current_time - last_check).total_seconds() < 7 * 24 * 60 * 60:
+                pypi_version = state.state["pypi_version"]
+
+        # Refresh the version if we need to or just see if we need to warn
+        if pypi_version is None:
+            # Lets use PackageFinder to see what the latest pip version is
+            finder = PackageFinder(
+                find_links=options.find_links,
+                index_urls=[options.index_url] + options.extra_index_urls,
+                allow_all_prereleases=False,  # Explicitly set to False
+                trusted_hosts=options.trusted_hosts,
+                session=session,
+            )
+            all_candidates = finder.find_all_candidates("pip")
+            if not all_candidates:
+                return
+            pypi_version = str(
+                max(all_candidates, key=lambda c: c.version).version
+            )
+
+            # save that we've performed a check
+            state.save(pypi_version, current_time)
+
+        remote_version = packaging_version.parse(pypi_version)
+
+        # Determine if our pypi_version is older
+        if (pip_version < remote_version and
+                pip_version.base_version != remote_version.base_version and
+                was_installed_by_pip('pip')):
+            # Advise "python -m pip" on Windows to avoid issues
+            # with overwriting pip.exe.
+            if WINDOWS:
+                pip_cmd = "python -m pip"
+            else:
+                pip_cmd = "pip"
+            logger.warning(
+                "You are using pip version %s, however version %s is "
+                "available.\nYou should consider upgrading via the "
+                "'%s install --upgrade pip' command.",
+                pip_version, pypi_version, pip_cmd
+            )
+    except Exception:
+        logger.debug(
+            "There was an error checking the latest version of pip",
+            exc_info=True,
+        )
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/packaging.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/packaging.py
new file mode 100644
index 0000000..7aaf7b5
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/packaging.py
@@ -0,0 +1,85 @@
+from __future__ import absolute_import
+
+import logging
+import sys
+from email.parser import FeedParser
+
+from pip._vendor import pkg_resources
+from pip._vendor.packaging import specifiers, version
+
+from pip._internal import exceptions
+from pip._internal.utils.misc import display_path
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional  # noqa: F401
+    from email.message import Message  # noqa: F401
+    from pip._vendor.pkg_resources import Distribution  # noqa: F401
+
+
+logger = logging.getLogger(__name__)
+
+
+def check_requires_python(requires_python):
+    # type: (Optional[str]) -> bool
+    """
+    Check if the python version in use match the `requires_python` specifier.
+
+    Returns `True` if the version of python in use matches the requirement.
+    Returns `False` if the version of python in use does not matches the
+    requirement.
+
+    Raises an InvalidSpecifier if `requires_python` have an invalid format.
+    """
+    if requires_python is None:
+        # The package provides no information
+        return True
+    requires_python_specifier = specifiers.SpecifierSet(requires_python)
+
+    # We only use major.minor.micro
+    python_version = version.parse('.'.join(map(str, sys.version_info[:3])))
+    return python_version in requires_python_specifier
+
+
+def get_metadata(dist):
+    # type: (Distribution) -> Message
+    if (isinstance(dist, pkg_resources.DistInfoDistribution) and
+            dist.has_metadata('METADATA')):
+        metadata = dist.get_metadata('METADATA')
+    elif dist.has_metadata('PKG-INFO'):
+        metadata = dist.get_metadata('PKG-INFO')
+    else:
+        logger.warning("No metadata found in %s", display_path(dist.location))
+        metadata = ''
+
+    feed_parser = FeedParser()
+    feed_parser.feed(metadata)
+    return feed_parser.close()
+
+
+def check_dist_requires_python(dist):
+    pkg_info_dict = get_metadata(dist)
+    requires_python = pkg_info_dict.get('Requires-Python')
+    try:
+        if not check_requires_python(requires_python):
+            raise exceptions.UnsupportedPythonVersion(
+                "%s requires Python '%s' but the running Python is %s" % (
+                    dist.project_name,
+                    requires_python,
+                    '.'.join(map(str, sys.version_info[:3])),)
+            )
+    except specifiers.InvalidSpecifier as e:
+        logger.warning(
+            "Package %s has an invalid Requires-Python entry %s - %s",
+            dist.project_name, requires_python, e,
+        )
+        return
+
+
+def get_installer(dist):
+    # type: (Distribution) -> str
+    if dist.has_metadata('INSTALLER'):
+        for line in dist.get_metadata_lines('INSTALLER'):
+            if line.strip():
+                return line.strip()
+    return ''
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/setuptools_build.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/setuptools_build.py
new file mode 100644
index 0000000..03973e9
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/setuptools_build.py
@@ -0,0 +1,8 @@
+# Shim to wrap setup.py invocation with setuptools
+SETUPTOOLS_SHIM = (
+    "import setuptools, tokenize;__file__=%r;"
+    "f=getattr(tokenize, 'open', open)(__file__);"
+    "code=f.read().replace('\\r\\n', '\\n');"
+    "f.close();"
+    "exec(compile(code, __file__, 'exec'))"
+)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/temp_dir.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/temp_dir.py
new file mode 100644
index 0000000..2c81ad5
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/temp_dir.py
@@ -0,0 +1,155 @@
+from __future__ import absolute_import
+
+import errno
+import itertools
+import logging
+import os.path
+import tempfile
+
+from pip._internal.utils.misc import rmtree
+
+logger = logging.getLogger(__name__)
+
+
+class TempDirectory(object):
+    """Helper class that owns and cleans up a temporary directory.
+
+    This class can be used as a context manager or as an OO representation of a
+    temporary directory.
+
+    Attributes:
+        path
+            Location to the created temporary directory or None
+        delete
+            Whether the directory should be deleted when exiting
+            (when used as a contextmanager)
+
+    Methods:
+        create()
+            Creates a temporary directory and stores its path in the path
+            attribute.
+        cleanup()
+            Deletes the temporary directory and sets path attribute to None
+
+    When used as a context manager, a temporary directory is created on
+    entering the context and, if the delete attribute is True, on exiting the
+    context the created directory is deleted.
+    """
+
+    def __init__(self, path=None, delete=None, kind="temp"):
+        super(TempDirectory, self).__init__()
+
+        if path is None and delete is None:
+            # If we were not given an explicit directory, and we were not given
+            # an explicit delete option, then we'll default to deleting.
+            delete = True
+
+        self.path = path
+        self.delete = delete
+        self.kind = kind
+
+    def __repr__(self):
+        return "<{} {!r}>".format(self.__class__.__name__, self.path)
+
+    def __enter__(self):
+        self.create()
+        return self
+
+    def __exit__(self, exc, value, tb):
+        if self.delete:
+            self.cleanup()
+
+    def create(self):
+        """Create a temporary directory and store its path in self.path
+        """
+        if self.path is not None:
+            logger.debug(
+                "Skipped creation of temporary directory: {}".format(self.path)
+            )
+            return
+        # We realpath here because some systems have their default tmpdir
+        # symlinked to another directory.  This tends to confuse build
+        # scripts, so we canonicalize the path by traversing potential
+        # symlinks here.
+        self.path = os.path.realpath(
+            tempfile.mkdtemp(prefix="pip-{}-".format(self.kind))
+        )
+        logger.debug("Created temporary directory: {}".format(self.path))
+
+    def cleanup(self):
+        """Remove the temporary directory created and reset state
+        """
+        if self.path is not None and os.path.exists(self.path):
+            rmtree(self.path)
+        self.path = None
+
+
+class AdjacentTempDirectory(TempDirectory):
+    """Helper class that creates a temporary directory adjacent to a real one.
+
+    Attributes:
+        original
+            The original directory to create a temp directory for.
+        path
+            After calling create() or entering, contains the full
+            path to the temporary directory.
+        delete
+            Whether the directory should be deleted when exiting
+            (when used as a contextmanager)
+
+    """
+    # The characters that may be used to name the temp directory
+    # We always prepend a ~ and then rotate through these until
+    # a usable name is found.
+    # pkg_resources raises a different error for .dist-info folder
+    # with leading '-' and invalid metadata
+    LEADING_CHARS = "-~.=%0123456789"
+
+    def __init__(self, original, delete=None):
+        super(AdjacentTempDirectory, self).__init__(delete=delete)
+        self.original = original.rstrip('/\\')
+
+    @classmethod
+    def _generate_names(cls, name):
+        """Generates a series of temporary names.
+
+        The algorithm replaces the leading characters in the name
+        with ones that are valid filesystem characters, but are not
+        valid package names (for both Python and pip definitions of
+        package).
+        """
+        for i in range(1, len(name)):
+            for candidate in itertools.combinations_with_replacement(
+                    cls.LEADING_CHARS, i - 1):
+                new_name = '~' + ''.join(candidate) + name[i:]
+                if new_name != name:
+                    yield new_name
+
+        # If we make it this far, we will have to make a longer name
+        for i in range(len(cls.LEADING_CHARS)):
+            for candidate in itertools.combinations_with_replacement(
+                    cls.LEADING_CHARS, i):
+                new_name = '~' + ''.join(candidate) + name
+                if new_name != name:
+                    yield new_name
+
+    def create(self):
+        root, name = os.path.split(self.original)
+        for candidate in self._generate_names(name):
+            path = os.path.join(root, candidate)
+            try:
+                os.mkdir(path)
+            except OSError as ex:
+                # Continue if the name exists already
+                if ex.errno != errno.EEXIST:
+                    raise
+            else:
+                self.path = os.path.realpath(path)
+                break
+
+        if not self.path:
+            # Final fallback on the default behavior.
+            self.path = os.path.realpath(
+                tempfile.mkdtemp(prefix="pip-{}-".format(self.kind))
+            )
+        logger.debug("Created temporary directory: {}".format(self.path))
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/typing.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/typing.py
new file mode 100644
index 0000000..e085cdf
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/typing.py
@@ -0,0 +1,29 @@
+"""For neatly implementing static typing in pip.
+
+`mypy` - the static type analysis tool we use - uses the `typing` module, which
+provides core functionality fundamental to mypy's functioning.
+
+Generally, `typing` would be imported at runtime and used in that fashion -
+it acts as a no-op at runtime and does not have any run-time overhead by
+design.
+
+As it turns out, `typing` is not vendorable - it uses separate sources for
+Python 2/Python 3. Thus, this codebase can not expect it to be present.
+To work around this, mypy allows the typing import to be behind a False-y
+optional to prevent it from running at runtime and type-comments can be used
+to remove the need for the types to be accessible directly during runtime.
+
+This module provides the False-y guard in a nicely named fashion so that a
+curious maintainer can reach here to read this.
+
+In pip, all static-typing related imports should be guarded as follows:
+
+    from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+    if MYPY_CHECK_RUNNING:
+        from typing import ...  # noqa: F401
+
+Ref: https://github.com/python/mypy/issues/3216
+"""
+
+MYPY_CHECK_RUNNING = False
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/ui.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/ui.py
new file mode 100644
index 0000000..433675d
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/utils/ui.py
@@ -0,0 +1,441 @@
+from __future__ import absolute_import, division
+
+import contextlib
+import itertools
+import logging
+import sys
+import time
+from signal import SIGINT, default_int_handler, signal
+
+from pip._vendor import six
+from pip._vendor.progress.bar import (
+    Bar, ChargingBar, FillingCirclesBar, FillingSquaresBar, IncrementalBar,
+    ShadyBar,
+)
+from pip._vendor.progress.helpers import HIDE_CURSOR, SHOW_CURSOR, WritelnMixin
+from pip._vendor.progress.spinner import Spinner
+
+from pip._internal.utils.compat import WINDOWS
+from pip._internal.utils.logging import get_indentation
+from pip._internal.utils.misc import format_size
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Iterator, IO  # noqa: F401
+
+try:
+    from pip._vendor import colorama
+# Lots of different errors can come from this, including SystemError and
+# ImportError.
+except Exception:
+    colorama = None
+
+logger = logging.getLogger(__name__)
+
+
+def _select_progress_class(preferred, fallback):
+    encoding = getattr(preferred.file, "encoding", None)
+
+    # If we don't know what encoding this file is in, then we'll just assume
+    # that it doesn't support unicode and use the ASCII bar.
+    if not encoding:
+        return fallback
+
+    # Collect all of the possible characters we want to use with the preferred
+    # bar.
+    characters = [
+        getattr(preferred, "empty_fill", six.text_type()),
+        getattr(preferred, "fill", six.text_type()),
+    ]
+    characters += list(getattr(preferred, "phases", []))
+
+    # Try to decode the characters we're using for the bar using the encoding
+    # of the given file, if this works then we'll assume that we can use the
+    # fancier bar and if not we'll fall back to the plaintext bar.
+    try:
+        six.text_type().join(characters).encode(encoding)
+    except UnicodeEncodeError:
+        return fallback
+    else:
+        return preferred
+
+
+_BaseBar = _select_progress_class(IncrementalBar, Bar)  # type: Any
+
+
+class InterruptibleMixin(object):
+    """
+    Helper to ensure that self.finish() gets called on keyboard interrupt.
+
+    This allows downloads to be interrupted without leaving temporary state
+    (like hidden cursors) behind.
+
+    This class is similar to the progress library's existing SigIntMixin
+    helper, but as of version 1.2, that helper has the following problems:
+
+    1. It calls sys.exit().
+    2. It discards the existing SIGINT handler completely.
+    3. It leaves its own handler in place even after an uninterrupted finish,
+       which will have unexpected delayed effects if the user triggers an
+       unrelated keyboard interrupt some time after a progress-displaying
+       download has already completed, for example.
+    """
+
+    def __init__(self, *args, **kwargs):
+        """
+        Save the original SIGINT handler for later.
+        """
+        super(InterruptibleMixin, self).__init__(*args, **kwargs)
+
+        self.original_handler = signal(SIGINT, self.handle_sigint)
+
+        # If signal() returns None, the previous handler was not installed from
+        # Python, and we cannot restore it. This probably should not happen,
+        # but if it does, we must restore something sensible instead, at least.
+        # The least bad option should be Python's default SIGINT handler, which
+        # just raises KeyboardInterrupt.
+        if self.original_handler is None:
+            self.original_handler = default_int_handler
+
+    def finish(self):
+        """
+        Restore the original SIGINT handler after finishing.
+
+        This should happen regardless of whether the progress display finishes
+        normally, or gets interrupted.
+        """
+        super(InterruptibleMixin, self).finish()
+        signal(SIGINT, self.original_handler)
+
+    def handle_sigint(self, signum, frame):
+        """
+        Call self.finish() before delegating to the original SIGINT handler.
+
+        This handler should only be in place while the progress display is
+        active.
+        """
+        self.finish()
+        self.original_handler(signum, frame)
+
+
+class SilentBar(Bar):
+
+    def update(self):
+        pass
+
+
+class BlueEmojiBar(IncrementalBar):
+
+    suffix = "%(percent)d%%"
+    bar_prefix = " "
+    bar_suffix = " "
+    phases = (u"\U0001F539", u"\U0001F537", u"\U0001F535")  # type: Any
+
+
+class DownloadProgressMixin(object):
+
+    def __init__(self, *args, **kwargs):
+        super(DownloadProgressMixin, self).__init__(*args, **kwargs)
+        self.message = (" " * (get_indentation() + 2)) + self.message
+
+    @property
+    def downloaded(self):
+        return format_size(self.index)
+
+    @property
+    def download_speed(self):
+        # Avoid zero division errors...
+        if self.avg == 0.0:
+            return "..."
+        return format_size(1 / self.avg) + "/s"
+
+    @property
+    def pretty_eta(self):
+        if self.eta:
+            return "eta %s" % self.eta_td
+        return ""
+
+    def iter(self, it, n=1):
+        for x in it:
+            yield x
+            self.next(n)
+        self.finish()
+
+
+class WindowsMixin(object):
+
+    def __init__(self, *args, **kwargs):
+        # The Windows terminal does not support the hide/show cursor ANSI codes
+        # even with colorama. So we'll ensure that hide_cursor is False on
+        # Windows.
+        # This call neds to go before the super() call, so that hide_cursor
+        # is set in time. The base progress bar class writes the "hide cursor"
+        # code to the terminal in its init, so if we don't set this soon
+        # enough, we get a "hide" with no corresponding "show"...
+        if WINDOWS and self.hide_cursor:
+            self.hide_cursor = False
+
+        super(WindowsMixin, self).__init__(*args, **kwargs)
+
+        # Check if we are running on Windows and we have the colorama module,
+        # if we do then wrap our file with it.
+        if WINDOWS and colorama:
+            self.file = colorama.AnsiToWin32(self.file)
+            # The progress code expects to be able to call self.file.isatty()
+            # but the colorama.AnsiToWin32() object doesn't have that, so we'll
+            # add it.
+            self.file.isatty = lambda: self.file.wrapped.isatty()
+            # The progress code expects to be able to call self.file.flush()
+            # but the colorama.AnsiToWin32() object doesn't have that, so we'll
+            # add it.
+            self.file.flush = lambda: self.file.wrapped.flush()
+
+
+class BaseDownloadProgressBar(WindowsMixin, InterruptibleMixin,
+                              DownloadProgressMixin):
+
+    file = sys.stdout
+    message = "%(percent)d%%"
+    suffix = "%(downloaded)s %(download_speed)s %(pretty_eta)s"
+
+# NOTE: The "type: ignore" comments on the following classes are there to
+#       work around https://github.com/python/typing/issues/241
+
+
+class DefaultDownloadProgressBar(BaseDownloadProgressBar,
+                                 _BaseBar):
+    pass
+
+
+class DownloadSilentBar(BaseDownloadProgressBar, SilentBar):  # type: ignore
+    pass
+
+
+class DownloadIncrementalBar(BaseDownloadProgressBar,  # type: ignore
+                             IncrementalBar):
+    pass
+
+
+class DownloadChargingBar(BaseDownloadProgressBar,  # type: ignore
+                          ChargingBar):
+    pass
+
+
+class DownloadShadyBar(BaseDownloadProgressBar, ShadyBar):  # type: ignore
+    pass
+
+
+class DownloadFillingSquaresBar(BaseDownloadProgressBar,  # type: ignore
+                                FillingSquaresBar):
+    pass
+
+
+class DownloadFillingCirclesBar(BaseDownloadProgressBar,  # type: ignore
+                                FillingCirclesBar):
+    pass
+
+
+class DownloadBlueEmojiProgressBar(BaseDownloadProgressBar,  # type: ignore
+                                   BlueEmojiBar):
+    pass
+
+
+class DownloadProgressSpinner(WindowsMixin, InterruptibleMixin,
+                              DownloadProgressMixin, WritelnMixin, Spinner):
+
+    file = sys.stdout
+    suffix = "%(downloaded)s %(download_speed)s"
+
+    def next_phase(self):
+        if not hasattr(self, "_phaser"):
+            self._phaser = itertools.cycle(self.phases)
+        return next(self._phaser)
+
+    def update(self):
+        message = self.message % self
+        phase = self.next_phase()
+        suffix = self.suffix % self
+        line = ''.join([
+            message,
+            " " if message else "",
+            phase,
+            " " if suffix else "",
+            suffix,
+        ])
+
+        self.writeln(line)
+
+
+BAR_TYPES = {
+    "off": (DownloadSilentBar, DownloadSilentBar),
+    "on": (DefaultDownloadProgressBar, DownloadProgressSpinner),
+    "ascii": (DownloadIncrementalBar, DownloadProgressSpinner),
+    "pretty": (DownloadFillingCirclesBar, DownloadProgressSpinner),
+    "emoji": (DownloadBlueEmojiProgressBar, DownloadProgressSpinner)
+}
+
+
+def DownloadProgressProvider(progress_bar, max=None):
+    if max is None or max == 0:
+        return BAR_TYPES[progress_bar][1]().iter
+    else:
+        return BAR_TYPES[progress_bar][0](max=max).iter
+
+
+################################################################
+# Generic "something is happening" spinners
+#
+# We don't even try using progress.spinner.Spinner here because it's actually
+# simpler to reimplement from scratch than to coerce their code into doing
+# what we need.
+################################################################
+
+@contextlib.contextmanager
+def hidden_cursor(file):
+    # type: (IO) -> Iterator[None]
+    # The Windows terminal does not support the hide/show cursor ANSI codes,
+    # even via colorama. So don't even try.
+    if WINDOWS:
+        yield
+    # We don't want to clutter the output with control characters if we're
+    # writing to a file, or if the user is running with --quiet.
+    # See https://github.com/pypa/pip/issues/3418
+    elif not file.isatty() or logger.getEffectiveLevel() > logging.INFO:
+        yield
+    else:
+        file.write(HIDE_CURSOR)
+        try:
+            yield
+        finally:
+            file.write(SHOW_CURSOR)
+
+
+class RateLimiter(object):
+    def __init__(self, min_update_interval_seconds):
+        # type: (float) -> None
+        self._min_update_interval_seconds = min_update_interval_seconds
+        self._last_update = 0  # type: float
+
+    def ready(self):
+        # type: () -> bool
+        now = time.time()
+        delta = now - self._last_update
+        return delta >= self._min_update_interval_seconds
+
+    def reset(self):
+        # type: () -> None
+        self._last_update = time.time()
+
+
+class SpinnerInterface(object):
+    def spin(self):
+        # type: () -> None
+        raise NotImplementedError()
+
+    def finish(self, final_status):
+        # type: (str) -> None
+        raise NotImplementedError()
+
+
+class InteractiveSpinner(SpinnerInterface):
+    def __init__(self, message, file=None, spin_chars="-\\|/",
+                 # Empirically, 8 updates/second looks nice
+                 min_update_interval_seconds=0.125):
+        self._message = message
+        if file is None:
+            file = sys.stdout
+        self._file = file
+        self._rate_limiter = RateLimiter(min_update_interval_seconds)
+        self._finished = False
+
+        self._spin_cycle = itertools.cycle(spin_chars)
+
+        self._file.write(" " * get_indentation() + self._message + " ... ")
+        self._width = 0
+
+    def _write(self, status):
+        assert not self._finished
+        # Erase what we wrote before by backspacing to the beginning, writing
+        # spaces to overwrite the old text, and then backspacing again
+        backup = "\b" * self._width
+        self._file.write(backup + " " * self._width + backup)
+        # Now we have a blank slate to add our status
+        self._file.write(status)
+        self._width = len(status)
+        self._file.flush()
+        self._rate_limiter.reset()
+
+    def spin(self):
+        # type: () -> None
+        if self._finished:
+            return
+        if not self._rate_limiter.ready():
+            return
+        self._write(next(self._spin_cycle))
+
+    def finish(self, final_status):
+        # type: (str) -> None
+        if self._finished:
+            return
+        self._write(final_status)
+        self._file.write("\n")
+        self._file.flush()
+        self._finished = True
+
+
+# Used for dumb terminals, non-interactive installs (no tty), etc.
+# We still print updates occasionally (once every 60 seconds by default) to
+# act as a keep-alive for systems like Travis-CI that take lack-of-output as
+# an indication that a task has frozen.
+class NonInteractiveSpinner(SpinnerInterface):
+    def __init__(self, message, min_update_interval_seconds=60):
+        # type: (str, float) -> None
+        self._message = message
+        self._finished = False
+        self._rate_limiter = RateLimiter(min_update_interval_seconds)
+        self._update("started")
+
+    def _update(self, status):
+        assert not self._finished
+        self._rate_limiter.reset()
+        logger.info("%s: %s", self._message, status)
+
+    def spin(self):
+        # type: () -> None
+        if self._finished:
+            return
+        if not self._rate_limiter.ready():
+            return
+        self._update("still running...")
+
+    def finish(self, final_status):
+        # type: (str) -> None
+        if self._finished:
+            return
+        self._update("finished with status '%s'" % (final_status,))
+        self._finished = True
+
+
+@contextlib.contextmanager
+def open_spinner(message):
+    # type: (str) -> Iterator[SpinnerInterface]
+    # Interactive spinner goes directly to sys.stdout rather than being routed
+    # through the logging system, but it acts like it has level INFO,
+    # i.e. it's only displayed if we're at level INFO or better.
+    # Non-interactive spinner goes through the logging system, so it is always
+    # in sync with logging configuration.
+    if sys.stdout.isatty() and logger.getEffectiveLevel() <= logging.INFO:
+        spinner = InteractiveSpinner(message)  # type: SpinnerInterface
+    else:
+        spinner = NonInteractiveSpinner(message)
+    try:
+        with hidden_cursor(sys.stdout):
+            yield spinner
+    except KeyboardInterrupt:
+        spinner.finish("canceled")
+        raise
+    except Exception:
+        spinner.finish("error")
+        raise
+    else:
+        spinner.finish("done")
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/__init__.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/__init__.py
new file mode 100644
index 0000000..9cba764
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/__init__.py
@@ -0,0 +1,534 @@
+"""Handles all VCS (version control) support"""
+from __future__ import absolute_import
+
+import errno
+import logging
+import os
+import shutil
+import sys
+
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+from pip._internal.exceptions import BadCommand
+from pip._internal.utils.misc import (
+    display_path, backup_dir, call_subprocess, rmtree, ask_path_exists,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Any, Dict, Iterable, List, Mapping, Optional, Text, Tuple, Type
+    )
+    from pip._internal.utils.ui import SpinnerInterface  # noqa: F401
+
+    AuthInfo = Tuple[Optional[str], Optional[str]]
+
+__all__ = ['vcs']
+
+
+logger = logging.getLogger(__name__)
+
+
+class RemoteNotFoundError(Exception):
+    pass
+
+
+class RevOptions(object):
+
+    """
+    Encapsulates a VCS-specific revision to install, along with any VCS
+    install options.
+
+    Instances of this class should be treated as if immutable.
+    """
+
+    def __init__(self, vcs, rev=None, extra_args=None):
+        # type: (VersionControl, Optional[str], Optional[List[str]]) -> None
+        """
+        Args:
+          vcs: a VersionControl object.
+          rev: the name of the revision to install.
+          extra_args: a list of extra options.
+        """
+        if extra_args is None:
+            extra_args = []
+
+        self.extra_args = extra_args
+        self.rev = rev
+        self.vcs = vcs
+
+    def __repr__(self):
+        return '<RevOptions {}: rev={!r}>'.format(self.vcs.name, self.rev)
+
+    @property
+    def arg_rev(self):
+        # type: () -> Optional[str]
+        if self.rev is None:
+            return self.vcs.default_arg_rev
+
+        return self.rev
+
+    def to_args(self):
+        # type: () -> List[str]
+        """
+        Return the VCS-specific command arguments.
+        """
+        args = []  # type: List[str]
+        rev = self.arg_rev
+        if rev is not None:
+            args += self.vcs.get_base_rev_args(rev)
+        args += self.extra_args
+
+        return args
+
+    def to_display(self):
+        # type: () -> str
+        if not self.rev:
+            return ''
+
+        return ' (to revision {})'.format(self.rev)
+
+    def make_new(self, rev):
+        # type: (str) -> RevOptions
+        """
+        Make a copy of the current instance, but with a new rev.
+
+        Args:
+          rev: the name of the revision for the new object.
+        """
+        return self.vcs.make_rev_options(rev, extra_args=self.extra_args)
+
+
+class VcsSupport(object):
+    _registry = {}  # type: Dict[str, Type[VersionControl]]
+    schemes = ['ssh', 'git', 'hg', 'bzr', 'sftp', 'svn']
+
+    def __init__(self):
+        # type: () -> None
+        # Register more schemes with urlparse for various version control
+        # systems
+        urllib_parse.uses_netloc.extend(self.schemes)
+        # Python >= 2.7.4, 3.3 doesn't have uses_fragment
+        if getattr(urllib_parse, 'uses_fragment', None):
+            urllib_parse.uses_fragment.extend(self.schemes)
+        super(VcsSupport, self).__init__()
+
+    def __iter__(self):
+        return self._registry.__iter__()
+
+    @property
+    def backends(self):
+        # type: () -> List[Type[VersionControl]]
+        return list(self._registry.values())
+
+    @property
+    def dirnames(self):
+        # type: () -> List[str]
+        return [backend.dirname for backend in self.backends]
+
+    @property
+    def all_schemes(self):
+        # type: () -> List[str]
+        schemes = []  # type: List[str]
+        for backend in self.backends:
+            schemes.extend(backend.schemes)
+        return schemes
+
+    def register(self, cls):
+        # type: (Type[VersionControl]) -> None
+        if not hasattr(cls, 'name'):
+            logger.warning('Cannot register VCS %s', cls.__name__)
+            return
+        if cls.name not in self._registry:
+            self._registry[cls.name] = cls
+            logger.debug('Registered VCS backend: %s', cls.name)
+
+    def unregister(self, cls=None, name=None):
+        # type: (Optional[Type[VersionControl]], Optional[str]) -> None
+        if name in self._registry:
+            del self._registry[name]
+        elif cls in self._registry.values():
+            del self._registry[cls.name]
+        else:
+            logger.warning('Cannot unregister because no class or name given')
+
+    def get_backend_type(self, location):
+        # type: (str) -> Optional[Type[VersionControl]]
+        """
+        Return the type of the version control backend if found at given
+        location, e.g. vcs.get_backend_type('/path/to/vcs/checkout')
+        """
+        for vc_type in self._registry.values():
+            if vc_type.controls_location(location):
+                logger.debug('Determine that %s uses VCS: %s',
+                             location, vc_type.name)
+                return vc_type
+        return None
+
+    def get_backend(self, name):
+        # type: (str) -> Optional[Type[VersionControl]]
+        name = name.lower()
+        if name in self._registry:
+            return self._registry[name]
+        return None
+
+
+vcs = VcsSupport()
+
+
+class VersionControl(object):
+    name = ''
+    dirname = ''
+    repo_name = ''
+    # List of supported schemes for this Version Control
+    schemes = ()  # type: Tuple[str, ...]
+    # Iterable of environment variable names to pass to call_subprocess().
+    unset_environ = ()  # type: Tuple[str, ...]
+    default_arg_rev = None  # type: Optional[str]
+
+    def __init__(self, url=None, *args, **kwargs):
+        self.url = url
+        super(VersionControl, self).__init__(*args, **kwargs)
+
+    def get_base_rev_args(self, rev):
+        """
+        Return the base revision arguments for a vcs command.
+
+        Args:
+          rev: the name of a revision to install.  Cannot be None.
+        """
+        raise NotImplementedError
+
+    def make_rev_options(self, rev=None, extra_args=None):
+        # type: (Optional[str], Optional[List[str]]) -> RevOptions
+        """
+        Return a RevOptions object.
+
+        Args:
+          rev: the name of a revision to install.
+          extra_args: a list of extra options.
+        """
+        return RevOptions(self, rev, extra_args=extra_args)
+
+    @classmethod
+    def _is_local_repository(cls, repo):
+        # type: (str) -> bool
+        """
+           posix absolute paths start with os.path.sep,
+           win32 ones start with drive (like c:\\folder)
+        """
+        drive, tail = os.path.splitdrive(repo)
+        return repo.startswith(os.path.sep) or bool(drive)
+
+    def export(self, location):
+        """
+        Export the repository at the url to the destination location
+        i.e. only download the files, without vcs informations
+        """
+        raise NotImplementedError
+
+    def get_netloc_and_auth(self, netloc, scheme):
+        """
+        Parse the repository URL's netloc, and return the new netloc to use
+        along with auth information.
+
+        Args:
+          netloc: the original repository URL netloc.
+          scheme: the repository URL's scheme without the vcs prefix.
+
+        This is mainly for the Subversion class to override, so that auth
+        information can be provided via the --username and --password options
+        instead of through the URL.  For other subclasses like Git without
+        such an option, auth information must stay in the URL.
+
+        Returns: (netloc, (username, password)).
+        """
+        return netloc, (None, None)
+
+    def get_url_rev_and_auth(self, url):
+        # type: (str) -> Tuple[str, Optional[str], AuthInfo]
+        """
+        Parse the repository URL to use, and return the URL, revision,
+        and auth info to use.
+
+        Returns: (url, rev, (username, password)).
+        """
+        scheme, netloc, path, query, frag = urllib_parse.urlsplit(url)
+        if '+' not in scheme:
+            raise ValueError(
+                "Sorry, {!r} is a malformed VCS url. "
+                "The format is <vcs>+<protocol>://<url>, "
+                "e.g. svn+http://myrepo/svn/MyApp#egg=MyApp".format(url)
+            )
+        # Remove the vcs prefix.
+        scheme = scheme.split('+', 1)[1]
+        netloc, user_pass = self.get_netloc_and_auth(netloc, scheme)
+        rev = None
+        if '@' in path:
+            path, rev = path.rsplit('@', 1)
+        url = urllib_parse.urlunsplit((scheme, netloc, path, query, ''))
+        return url, rev, user_pass
+
+    def make_rev_args(self, username, password):
+        """
+        Return the RevOptions "extra arguments" to use in obtain().
+        """
+        return []
+
+    def get_url_rev_options(self, url):
+        # type: (str) -> Tuple[str, RevOptions]
+        """
+        Return the URL and RevOptions object to use in obtain() and in
+        some cases export(), as a tuple (url, rev_options).
+        """
+        url, rev, user_pass = self.get_url_rev_and_auth(url)
+        username, password = user_pass
+        extra_args = self.make_rev_args(username, password)
+        rev_options = self.make_rev_options(rev, extra_args=extra_args)
+
+        return url, rev_options
+
+    def normalize_url(self, url):
+        # type: (str) -> str
+        """
+        Normalize a URL for comparison by unquoting it and removing any
+        trailing slash.
+        """
+        return urllib_parse.unquote(url).rstrip('/')
+
+    def compare_urls(self, url1, url2):
+        # type: (str, str) -> bool
+        """
+        Compare two repo URLs for identity, ignoring incidental differences.
+        """
+        return (self.normalize_url(url1) == self.normalize_url(url2))
+
+    def fetch_new(self, dest, url, rev_options):
+        """
+        Fetch a revision from a repository, in the case that this is the
+        first fetch from the repository.
+
+        Args:
+          dest: the directory to fetch the repository to.
+          rev_options: a RevOptions object.
+        """
+        raise NotImplementedError
+
+    def switch(self, dest, url, rev_options):
+        """
+        Switch the repo at ``dest`` to point to ``URL``.
+
+        Args:
+          rev_options: a RevOptions object.
+        """
+        raise NotImplementedError
+
+    def update(self, dest, url, rev_options):
+        """
+        Update an already-existing repo to the given ``rev_options``.
+
+        Args:
+          rev_options: a RevOptions object.
+        """
+        raise NotImplementedError
+
+    def is_commit_id_equal(self, dest, name):
+        """
+        Return whether the id of the current commit equals the given name.
+
+        Args:
+          dest: the repository directory.
+          name: a string name.
+        """
+        raise NotImplementedError
+
+    def obtain(self, dest):
+        # type: (str) -> None
+        """
+        Install or update in editable mode the package represented by this
+        VersionControl object.
+
+        Args:
+          dest: the repository directory in which to install or update.
+        """
+        url, rev_options = self.get_url_rev_options(self.url)
+
+        if not os.path.exists(dest):
+            self.fetch_new(dest, url, rev_options)
+            return
+
+        rev_display = rev_options.to_display()
+        if self.is_repository_directory(dest):
+            existing_url = self.get_remote_url(dest)
+            if self.compare_urls(existing_url, url):
+                logger.debug(
+                    '%s in %s exists, and has correct URL (%s)',
+                    self.repo_name.title(),
+                    display_path(dest),
+                    url,
+                )
+                if not self.is_commit_id_equal(dest, rev_options.rev):
+                    logger.info(
+                        'Updating %s %s%s',
+                        display_path(dest),
+                        self.repo_name,
+                        rev_display,
+                    )
+                    self.update(dest, url, rev_options)
+                else:
+                    logger.info('Skipping because already up-to-date.')
+                return
+
+            logger.warning(
+                '%s %s in %s exists with URL %s',
+                self.name,
+                self.repo_name,
+                display_path(dest),
+                existing_url,
+            )
+            prompt = ('(s)witch, (i)gnore, (w)ipe, (b)ackup ',
+                      ('s', 'i', 'w', 'b'))
+        else:
+            logger.warning(
+                'Directory %s already exists, and is not a %s %s.',
+                dest,
+                self.name,
+                self.repo_name,
+            )
+            # https://github.com/python/mypy/issues/1174
+            prompt = ('(i)gnore, (w)ipe, (b)ackup ',  # type: ignore
+                      ('i', 'w', 'b'))
+
+        logger.warning(
+            'The plan is to install the %s repository %s',
+            self.name,
+            url,
+        )
+        response = ask_path_exists('What to do?  %s' % prompt[0], prompt[1])
+
+        if response == 'a':
+            sys.exit(-1)
+
+        if response == 'w':
+            logger.warning('Deleting %s', display_path(dest))
+            rmtree(dest)
+            self.fetch_new(dest, url, rev_options)
+            return
+
+        if response == 'b':
+            dest_dir = backup_dir(dest)
+            logger.warning(
+                'Backing up %s to %s', display_path(dest), dest_dir,
+            )
+            shutil.move(dest, dest_dir)
+            self.fetch_new(dest, url, rev_options)
+            return
+
+        # Do nothing if the response is "i".
+        if response == 's':
+            logger.info(
+                'Switching %s %s to %s%s',
+                self.repo_name,
+                display_path(dest),
+                url,
+                rev_display,
+            )
+            self.switch(dest, url, rev_options)
+
+    def unpack(self, location):
+        # type: (str) -> None
+        """
+        Clean up current location and download the url repository
+        (and vcs infos) into location
+        """
+        if os.path.exists(location):
+            rmtree(location)
+        self.obtain(location)
+
+    @classmethod
+    def get_src_requirement(cls, location, project_name):
+        """
+        Return a string representing the requirement needed to
+        redownload the files currently present in location, something
+        like:
+          {repository_url}@{revision}#egg={project_name}-{version_identifier}
+        """
+        raise NotImplementedError
+
+    @classmethod
+    def get_remote_url(cls, location):
+        """
+        Return the url used at location
+
+        Raises RemoteNotFoundError if the repository does not have a remote
+        url configured.
+        """
+        raise NotImplementedError
+
+    @classmethod
+    def get_revision(cls, location):
+        """
+        Return the current commit id of the files at the given location.
+        """
+        raise NotImplementedError
+
+    @classmethod
+    def run_command(
+        cls,
+        cmd,  # type: List[str]
+        show_stdout=True,  # type: bool
+        cwd=None,  # type: Optional[str]
+        on_returncode='raise',  # type: str
+        extra_ok_returncodes=None,  # type: Optional[Iterable[int]]
+        command_desc=None,  # type: Optional[str]
+        extra_environ=None,  # type: Optional[Mapping[str, Any]]
+        spinner=None  # type: Optional[SpinnerInterface]
+    ):
+        # type: (...) -> Optional[Text]
+        """
+        Run a VCS subcommand
+        This is simply a wrapper around call_subprocess that adds the VCS
+        command name, and checks that the VCS is available
+        """
+        cmd = [cls.name] + cmd
+        try:
+            return call_subprocess(cmd, show_stdout, cwd,
+                                   on_returncode=on_returncode,
+                                   extra_ok_returncodes=extra_ok_returncodes,
+                                   command_desc=command_desc,
+                                   extra_environ=extra_environ,
+                                   unset_environ=cls.unset_environ,
+                                   spinner=spinner)
+        except OSError as e:
+            # errno.ENOENT = no such file or directory
+            # In other words, the VCS executable isn't available
+            if e.errno == errno.ENOENT:
+                raise BadCommand(
+                    'Cannot find command %r - do you have '
+                    '%r installed and in your '
+                    'PATH?' % (cls.name, cls.name))
+            else:
+                raise  # re-raise exception if a different error occurred
+
+    @classmethod
+    def is_repository_directory(cls, path):
+        # type: (str) -> bool
+        """
+        Return whether a directory path is a repository directory.
+        """
+        logger.debug('Checking in %s for %s (%s)...',
+                     path, cls.dirname, cls.name)
+        return os.path.exists(os.path.join(path, cls.dirname))
+
+    @classmethod
+    def controls_location(cls, location):
+        # type: (str) -> bool
+        """
+        Check if a location is controlled by the vcs.
+        It is meant to be overridden to implement smarter detection
+        mechanisms for specific vcs.
+
+        This can do more than is_repository_directory() alone.  For example,
+        the Git override checks that Git is actually available.
+        """
+        return cls.is_repository_directory(location)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/bazaar.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/bazaar.py
new file mode 100644
index 0000000..4c6ac79
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/bazaar.py
@@ -0,0 +1,114 @@
+from __future__ import absolute_import
+
+import logging
+import os
+
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+from pip._internal.download import path_to_url
+from pip._internal.utils.misc import (
+    display_path, make_vcs_requirement_url, rmtree,
+)
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.vcs import VersionControl, vcs
+
+logger = logging.getLogger(__name__)
+
+
+class Bazaar(VersionControl):
+    name = 'bzr'
+    dirname = '.bzr'
+    repo_name = 'branch'
+    schemes = (
+        'bzr', 'bzr+http', 'bzr+https', 'bzr+ssh', 'bzr+sftp', 'bzr+ftp',
+        'bzr+lp',
+    )
+
+    def __init__(self, url=None, *args, **kwargs):
+        super(Bazaar, self).__init__(url, *args, **kwargs)
+        # This is only needed for python <2.7.5
+        # Register lp but do not expose as a scheme to support bzr+lp.
+        if getattr(urllib_parse, 'uses_fragment', None):
+            urllib_parse.uses_fragment.extend(['lp'])
+
+    def get_base_rev_args(self, rev):
+        return ['-r', rev]
+
+    def export(self, location):
+        """
+        Export the Bazaar repository at the url to the destination location
+        """
+        # Remove the location to make sure Bazaar can export it correctly
+        if os.path.exists(location):
+            rmtree(location)
+
+        with TempDirectory(kind="export") as temp_dir:
+            self.unpack(temp_dir.path)
+
+            self.run_command(
+                ['export', location],
+                cwd=temp_dir.path, show_stdout=False,
+            )
+
+    def fetch_new(self, dest, url, rev_options):
+        rev_display = rev_options.to_display()
+        logger.info(
+            'Checking out %s%s to %s',
+            url,
+            rev_display,
+            display_path(dest),
+        )
+        cmd_args = ['branch', '-q'] + rev_options.to_args() + [url, dest]
+        self.run_command(cmd_args)
+
+    def switch(self, dest, url, rev_options):
+        self.run_command(['switch', url], cwd=dest)
+
+    def update(self, dest, url, rev_options):
+        cmd_args = ['pull', '-q'] + rev_options.to_args()
+        self.run_command(cmd_args, cwd=dest)
+
+    def get_url_rev_and_auth(self, url):
+        # hotfix the URL scheme after removing bzr+ from bzr+ssh:// readd it
+        url, rev, user_pass = super(Bazaar, self).get_url_rev_and_auth(url)
+        if url.startswith('ssh://'):
+            url = 'bzr+' + url
+        return url, rev, user_pass
+
+    @classmethod
+    def get_remote_url(cls, location):
+        urls = cls.run_command(['info'], show_stdout=False, cwd=location)
+        for line in urls.splitlines():
+            line = line.strip()
+            for x in ('checkout of branch: ',
+                      'parent branch: '):
+                if line.startswith(x):
+                    repo = line.split(x)[1]
+                    if cls._is_local_repository(repo):
+                        return path_to_url(repo)
+                    return repo
+        return None
+
+    @classmethod
+    def get_revision(cls, location):
+        revision = cls.run_command(
+            ['revno'], show_stdout=False, cwd=location,
+        )
+        return revision.splitlines()[-1]
+
+    @classmethod
+    def get_src_requirement(cls, location, project_name):
+        repo = cls.get_remote_url(location)
+        if not repo:
+            return None
+        if not repo.lower().startswith('bzr:'):
+            repo = 'bzr+' + repo
+        current_rev = cls.get_revision(location)
+        return make_vcs_requirement_url(repo, current_rev, project_name)
+
+    def is_commit_id_equal(self, dest, name):
+        """Always assume the versions don't match"""
+        return False
+
+
+vcs.register(Bazaar)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/git.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/git.py
new file mode 100644
index 0000000..dd2bd61
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/git.py
@@ -0,0 +1,369 @@
+from __future__ import absolute_import
+
+import logging
+import os.path
+import re
+
+from pip._vendor.packaging.version import parse as parse_version
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+from pip._vendor.six.moves.urllib import request as urllib_request
+
+from pip._internal.exceptions import BadCommand
+from pip._internal.utils.compat import samefile
+from pip._internal.utils.misc import (
+    display_path, make_vcs_requirement_url, redact_password_from_url,
+)
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.vcs import RemoteNotFoundError, VersionControl, vcs
+
+urlsplit = urllib_parse.urlsplit
+urlunsplit = urllib_parse.urlunsplit
+
+
+logger = logging.getLogger(__name__)
+
+
+HASH_REGEX = re.compile('[a-fA-F0-9]{40}')
+
+
+def looks_like_hash(sha):
+    return bool(HASH_REGEX.match(sha))
+
+
+class Git(VersionControl):
+    name = 'git'
+    dirname = '.git'
+    repo_name = 'clone'
+    schemes = (
+        'git', 'git+http', 'git+https', 'git+ssh', 'git+git', 'git+file',
+    )
+    # Prevent the user's environment variables from interfering with pip:
+    # https://github.com/pypa/pip/issues/1130
+    unset_environ = ('GIT_DIR', 'GIT_WORK_TREE')
+    default_arg_rev = 'HEAD'
+
+    def __init__(self, url=None, *args, **kwargs):
+
+        # Works around an apparent Git bug
+        # (see https://article.gmane.org/gmane.comp.version-control.git/146500)
+        if url:
+            scheme, netloc, path, query, fragment = urlsplit(url)
+            if scheme.endswith('file'):
+                initial_slashes = path[:-len(path.lstrip('/'))]
+                newpath = (
+                    initial_slashes +
+                    urllib_request.url2pathname(path)
+                    .replace('\\', '/').lstrip('/')
+                )
+                url = urlunsplit((scheme, netloc, newpath, query, fragment))
+                after_plus = scheme.find('+') + 1
+                url = scheme[:after_plus] + urlunsplit(
+                    (scheme[after_plus:], netloc, newpath, query, fragment),
+                )
+
+        super(Git, self).__init__(url, *args, **kwargs)
+
+    def get_base_rev_args(self, rev):
+        return [rev]
+
+    def get_git_version(self):
+        VERSION_PFX = 'git version '
+        version = self.run_command(['version'], show_stdout=False)
+        if version.startswith(VERSION_PFX):
+            version = version[len(VERSION_PFX):].split()[0]
+        else:
+            version = ''
+        # get first 3 positions of the git version becasue
+        # on windows it is x.y.z.windows.t, and this parses as
+        # LegacyVersion which always smaller than a Version.
+        version = '.'.join(version.split('.')[:3])
+        return parse_version(version)
+
+    def get_current_branch(self, location):
+        """
+        Return the current branch, or None if HEAD isn't at a branch
+        (e.g. detached HEAD).
+        """
+        # git-symbolic-ref exits with empty stdout if "HEAD" is a detached
+        # HEAD rather than a symbolic ref.  In addition, the -q causes the
+        # command to exit with status code 1 instead of 128 in this case
+        # and to suppress the message to stderr.
+        args = ['symbolic-ref', '-q', 'HEAD']
+        output = self.run_command(
+            args, extra_ok_returncodes=(1, ), show_stdout=False, cwd=location,
+        )
+        ref = output.strip()
+
+        if ref.startswith('refs/heads/'):
+            return ref[len('refs/heads/'):]
+
+        return None
+
+    def export(self, location):
+        """Export the Git repository at the url to the destination location"""
+        if not location.endswith('/'):
+            location = location + '/'
+
+        with TempDirectory(kind="export") as temp_dir:
+            self.unpack(temp_dir.path)
+            self.run_command(
+                ['checkout-index', '-a', '-f', '--prefix', location],
+                show_stdout=False, cwd=temp_dir.path
+            )
+
+    def get_revision_sha(self, dest, rev):
+        """
+        Return (sha_or_none, is_branch), where sha_or_none is a commit hash
+        if the revision names a remote branch or tag, otherwise None.
+
+        Args:
+          dest: the repository directory.
+          rev: the revision name.
+        """
+        # Pass rev to pre-filter the list.
+        output = self.run_command(['show-ref', rev], cwd=dest,
+                                  show_stdout=False, on_returncode='ignore')
+        refs = {}
+        for line in output.strip().splitlines():
+            try:
+                sha, ref = line.split()
+            except ValueError:
+                # Include the offending line to simplify troubleshooting if
+                # this error ever occurs.
+                raise ValueError('unexpected show-ref line: {!r}'.format(line))
+
+            refs[ref] = sha
+
+        branch_ref = 'refs/remotes/origin/{}'.format(rev)
+        tag_ref = 'refs/tags/{}'.format(rev)
+
+        sha = refs.get(branch_ref)
+        if sha is not None:
+            return (sha, True)
+
+        sha = refs.get(tag_ref)
+
+        return (sha, False)
+
+    def resolve_revision(self, dest, url, rev_options):
+        """
+        Resolve a revision to a new RevOptions object with the SHA1 of the
+        branch, tag, or ref if found.
+
+        Args:
+          rev_options: a RevOptions object.
+        """
+        rev = rev_options.arg_rev
+        sha, is_branch = self.get_revision_sha(dest, rev)
+
+        if sha is not None:
+            rev_options = rev_options.make_new(sha)
+            rev_options.branch_name = rev if is_branch else None
+
+            return rev_options
+
+        # Do not show a warning for the common case of something that has
+        # the form of a Git commit hash.
+        if not looks_like_hash(rev):
+            logger.warning(
+                "Did not find branch or tag '%s', assuming revision or ref.",
+                rev,
+            )
+
+        if not rev.startswith('refs/'):
+            return rev_options
+
+        # If it looks like a ref, we have to fetch it explicitly.
+        self.run_command(
+            ['fetch', '-q', url] + rev_options.to_args(),
+            cwd=dest,
+        )
+        # Change the revision to the SHA of the ref we fetched
+        sha = self.get_revision(dest, rev='FETCH_HEAD')
+        rev_options = rev_options.make_new(sha)
+
+        return rev_options
+
+    def is_commit_id_equal(self, dest, name):
+        """
+        Return whether the current commit hash equals the given name.
+
+        Args:
+          dest: the repository directory.
+          name: a string name.
+        """
+        if not name:
+            # Then avoid an unnecessary subprocess call.
+            return False
+
+        return self.get_revision(dest) == name
+
+    def fetch_new(self, dest, url, rev_options):
+        rev_display = rev_options.to_display()
+        logger.info(
+            'Cloning %s%s to %s', redact_password_from_url(url),
+            rev_display, display_path(dest),
+        )
+        self.run_command(['clone', '-q', url, dest])
+
+        if rev_options.rev:
+            # Then a specific revision was requested.
+            rev_options = self.resolve_revision(dest, url, rev_options)
+            branch_name = getattr(rev_options, 'branch_name', None)
+            if branch_name is None:
+                # Only do a checkout if the current commit id doesn't match
+                # the requested revision.
+                if not self.is_commit_id_equal(dest, rev_options.rev):
+                    cmd_args = ['checkout', '-q'] + rev_options.to_args()
+                    self.run_command(cmd_args, cwd=dest)
+            elif self.get_current_branch(dest) != branch_name:
+                # Then a specific branch was requested, and that branch
+                # is not yet checked out.
+                track_branch = 'origin/{}'.format(branch_name)
+                cmd_args = [
+                    'checkout', '-b', branch_name, '--track', track_branch,
+                ]
+                self.run_command(cmd_args, cwd=dest)
+
+        #: repo may contain submodules
+        self.update_submodules(dest)
+
+    def switch(self, dest, url, rev_options):
+        self.run_command(['config', 'remote.origin.url', url], cwd=dest)
+        cmd_args = ['checkout', '-q'] + rev_options.to_args()
+        self.run_command(cmd_args, cwd=dest)
+
+        self.update_submodules(dest)
+
+    def update(self, dest, url, rev_options):
+        # First fetch changes from the default remote
+        if self.get_git_version() >= parse_version('1.9.0'):
+            # fetch tags in addition to everything else
+            self.run_command(['fetch', '-q', '--tags'], cwd=dest)
+        else:
+            self.run_command(['fetch', '-q'], cwd=dest)
+        # Then reset to wanted revision (maybe even origin/master)
+        rev_options = self.resolve_revision(dest, url, rev_options)
+        cmd_args = ['reset', '--hard', '-q'] + rev_options.to_args()
+        self.run_command(cmd_args, cwd=dest)
+        #: update submodules
+        self.update_submodules(dest)
+
+    @classmethod
+    def get_remote_url(cls, location):
+        """
+        Return URL of the first remote encountered.
+
+        Raises RemoteNotFoundError if the repository does not have a remote
+        url configured.
+        """
+        # We need to pass 1 for extra_ok_returncodes since the command
+        # exits with return code 1 if there are no matching lines.
+        stdout = cls.run_command(
+            ['config', '--get-regexp', r'remote\..*\.url'],
+            extra_ok_returncodes=(1, ), show_stdout=False, cwd=location,
+        )
+        remotes = stdout.splitlines()
+        try:
+            found_remote = remotes[0]
+        except IndexError:
+            raise RemoteNotFoundError
+
+        for remote in remotes:
+            if remote.startswith('remote.origin.url '):
+                found_remote = remote
+                break
+        url = found_remote.split(' ')[1]
+        return url.strip()
+
+    @classmethod
+    def get_revision(cls, location, rev=None):
+        if rev is None:
+            rev = 'HEAD'
+        current_rev = cls.run_command(
+            ['rev-parse', rev], show_stdout=False, cwd=location,
+        )
+        return current_rev.strip()
+
+    @classmethod
+    def _get_subdirectory(cls, location):
+        """Return the relative path of setup.py to the git repo root."""
+        # find the repo root
+        git_dir = cls.run_command(['rev-parse', '--git-dir'],
+                                  show_stdout=False, cwd=location).strip()
+        if not os.path.isabs(git_dir):
+            git_dir = os.path.join(location, git_dir)
+        root_dir = os.path.join(git_dir, '..')
+        # find setup.py
+        orig_location = location
+        while not os.path.exists(os.path.join(location, 'setup.py')):
+            last_location = location
+            location = os.path.dirname(location)
+            if location == last_location:
+                # We've traversed up to the root of the filesystem without
+                # finding setup.py
+                logger.warning(
+                    "Could not find setup.py for directory %s (tried all "
+                    "parent directories)",
+                    orig_location,
+                )
+                return None
+        # relative path of setup.py to repo root
+        if samefile(root_dir, location):
+            return None
+        return os.path.relpath(location, root_dir)
+
+    @classmethod
+    def get_src_requirement(cls, location, project_name):
+        repo = cls.get_remote_url(location)
+        if not repo.lower().startswith('git:'):
+            repo = 'git+' + repo
+        current_rev = cls.get_revision(location)
+        subdir = cls._get_subdirectory(location)
+        req = make_vcs_requirement_url(repo, current_rev, project_name,
+                                       subdir=subdir)
+
+        return req
+
+    def get_url_rev_and_auth(self, url):
+        """
+        Prefixes stub URLs like 'user@hostname:user/repo.git' with 'ssh://'.
+        That's required because although they use SSH they sometimes don't
+        work with a ssh:// scheme (e.g. GitHub). But we need a scheme for
+        parsing. Hence we remove it again afterwards and return it as a stub.
+        """
+        if '://' not in url:
+            assert 'file:' not in url
+            url = url.replace('git+', 'git+ssh://')
+            url, rev, user_pass = super(Git, self).get_url_rev_and_auth(url)
+            url = url.replace('ssh://', '')
+        else:
+            url, rev, user_pass = super(Git, self).get_url_rev_and_auth(url)
+
+        return url, rev, user_pass
+
+    def update_submodules(self, location):
+        if not os.path.exists(os.path.join(location, '.gitmodules')):
+            return
+        self.run_command(
+            ['submodule', 'update', '--init', '--recursive', '-q'],
+            cwd=location,
+        )
+
+    @classmethod
+    def controls_location(cls, location):
+        if super(Git, cls).controls_location(location):
+            return True
+        try:
+            r = cls.run_command(['rev-parse'],
+                                cwd=location,
+                                show_stdout=False,
+                                on_returncode='ignore')
+            return not r
+        except BadCommand:
+            logger.debug("could not determine if %s is under git control "
+                         "because git is not available", location)
+            return False
+
+
+vcs.register(Git)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/mercurial.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/mercurial.py
new file mode 100644
index 0000000..26e75de
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/mercurial.py
@@ -0,0 +1,103 @@
+from __future__ import absolute_import
+
+import logging
+import os
+
+from pip._vendor.six.moves import configparser
+
+from pip._internal.download import path_to_url
+from pip._internal.utils.misc import display_path, make_vcs_requirement_url
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.vcs import VersionControl, vcs
+
+logger = logging.getLogger(__name__)
+
+
+class Mercurial(VersionControl):
+    name = 'hg'
+    dirname = '.hg'
+    repo_name = 'clone'
+    schemes = ('hg', 'hg+http', 'hg+https', 'hg+ssh', 'hg+static-http')
+
+    def get_base_rev_args(self, rev):
+        return [rev]
+
+    def export(self, location):
+        """Export the Hg repository at the url to the destination location"""
+        with TempDirectory(kind="export") as temp_dir:
+            self.unpack(temp_dir.path)
+
+            self.run_command(
+                ['archive', location], show_stdout=False, cwd=temp_dir.path
+            )
+
+    def fetch_new(self, dest, url, rev_options):
+        rev_display = rev_options.to_display()
+        logger.info(
+            'Cloning hg %s%s to %s',
+            url,
+            rev_display,
+            display_path(dest),
+        )
+        self.run_command(['clone', '--noupdate', '-q', url, dest])
+        cmd_args = ['update', '-q'] + rev_options.to_args()
+        self.run_command(cmd_args, cwd=dest)
+
+    def switch(self, dest, url, rev_options):
+        repo_config = os.path.join(dest, self.dirname, 'hgrc')
+        config = configparser.SafeConfigParser()
+        try:
+            config.read(repo_config)
+            config.set('paths', 'default', url)
+            with open(repo_config, 'w') as config_file:
+                config.write(config_file)
+        except (OSError, configparser.NoSectionError) as exc:
+            logger.warning(
+                'Could not switch Mercurial repository to %s: %s', url, exc,
+            )
+        else:
+            cmd_args = ['update', '-q'] + rev_options.to_args()
+            self.run_command(cmd_args, cwd=dest)
+
+    def update(self, dest, url, rev_options):
+        self.run_command(['pull', '-q'], cwd=dest)
+        cmd_args = ['update', '-q'] + rev_options.to_args()
+        self.run_command(cmd_args, cwd=dest)
+
+    @classmethod
+    def get_remote_url(cls, location):
+        url = cls.run_command(
+            ['showconfig', 'paths.default'],
+            show_stdout=False, cwd=location).strip()
+        if cls._is_local_repository(url):
+            url = path_to_url(url)
+        return url.strip()
+
+    @classmethod
+    def get_revision(cls, location):
+        current_revision = cls.run_command(
+            ['parents', '--template={rev}'],
+            show_stdout=False, cwd=location).strip()
+        return current_revision
+
+    @classmethod
+    def get_revision_hash(cls, location):
+        current_rev_hash = cls.run_command(
+            ['parents', '--template={node}'],
+            show_stdout=False, cwd=location).strip()
+        return current_rev_hash
+
+    @classmethod
+    def get_src_requirement(cls, location, project_name):
+        repo = cls.get_remote_url(location)
+        if not repo.lower().startswith('hg:'):
+            repo = 'hg+' + repo
+        current_rev_hash = cls.get_revision_hash(location)
+        return make_vcs_requirement_url(repo, current_rev_hash, project_name)
+
+    def is_commit_id_equal(self, dest, name):
+        """Always assume the versions don't match"""
+        return False
+
+
+vcs.register(Mercurial)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/subversion.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/subversion.py
new file mode 100644
index 0000000..42ac5ac
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/vcs/subversion.py
@@ -0,0 +1,200 @@
+from __future__ import absolute_import
+
+import logging
+import os
+import re
+
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    display_path, make_vcs_requirement_url, rmtree, split_auth_from_netloc,
+)
+from pip._internal.vcs import VersionControl, vcs
+
+_svn_xml_url_re = re.compile('url="([^"]+)"')
+_svn_rev_re = re.compile(r'committed-rev="(\d+)"')
+_svn_info_xml_rev_re = re.compile(r'\s*revision="(\d+)"')
+_svn_info_xml_url_re = re.compile(r'<url>(.*)</url>')
+
+
+logger = logging.getLogger(__name__)
+
+
+class Subversion(VersionControl):
+    name = 'svn'
+    dirname = '.svn'
+    repo_name = 'checkout'
+    schemes = ('svn', 'svn+ssh', 'svn+http', 'svn+https', 'svn+svn')
+
+    def get_base_rev_args(self, rev):
+        return ['-r', rev]
+
+    def export(self, location):
+        """Export the svn repository at the url to the destination location"""
+        url, rev_options = self.get_url_rev_options(self.url)
+
+        logger.info('Exporting svn repository %s to %s', url, location)
+        with indent_log():
+            if os.path.exists(location):
+                # Subversion doesn't like to check out over an existing
+                # directory --force fixes this, but was only added in svn 1.5
+                rmtree(location)
+            cmd_args = ['export'] + rev_options.to_args() + [url, location]
+            self.run_command(cmd_args, show_stdout=False)
+
+    def fetch_new(self, dest, url, rev_options):
+        rev_display = rev_options.to_display()
+        logger.info(
+            'Checking out %s%s to %s',
+            url,
+            rev_display,
+            display_path(dest),
+        )
+        cmd_args = ['checkout', '-q'] + rev_options.to_args() + [url, dest]
+        self.run_command(cmd_args)
+
+    def switch(self, dest, url, rev_options):
+        cmd_args = ['switch'] + rev_options.to_args() + [url, dest]
+        self.run_command(cmd_args)
+
+    def update(self, dest, url, rev_options):
+        cmd_args = ['update'] + rev_options.to_args() + [dest]
+        self.run_command(cmd_args)
+
+    @classmethod
+    def get_revision(cls, location):
+        """
+        Return the maximum revision for all files under a given location
+        """
+        # Note: taken from setuptools.command.egg_info
+        revision = 0
+
+        for base, dirs, files in os.walk(location):
+            if cls.dirname not in dirs:
+                dirs[:] = []
+                continue    # no sense walking uncontrolled subdirs
+            dirs.remove(cls.dirname)
+            entries_fn = os.path.join(base, cls.dirname, 'entries')
+            if not os.path.exists(entries_fn):
+                # FIXME: should we warn?
+                continue
+
+            dirurl, localrev = cls._get_svn_url_rev(base)
+
+            if base == location:
+                base = dirurl + '/'   # save the root url
+            elif not dirurl or not dirurl.startswith(base):
+                dirs[:] = []
+                continue    # not part of the same svn tree, skip it
+            revision = max(revision, localrev)
+        return revision
+
+    def get_netloc_and_auth(self, netloc, scheme):
+        """
+        This override allows the auth information to be passed to svn via the
+        --username and --password options instead of via the URL.
+        """
+        if scheme == 'ssh':
+            # The --username and --password options can't be used for
+            # svn+ssh URLs, so keep the auth information in the URL.
+            return super(Subversion, self).get_netloc_and_auth(
+                netloc, scheme)
+
+        return split_auth_from_netloc(netloc)
+
+    def get_url_rev_and_auth(self, url):
+        # hotfix the URL scheme after removing svn+ from svn+ssh:// readd it
+        url, rev, user_pass = super(Subversion, self).get_url_rev_and_auth(url)
+        if url.startswith('ssh://'):
+            url = 'svn+' + url
+        return url, rev, user_pass
+
+    def make_rev_args(self, username, password):
+        extra_args = []
+        if username:
+            extra_args += ['--username', username]
+        if password:
+            extra_args += ['--password', password]
+
+        return extra_args
+
+    @classmethod
+    def get_remote_url(cls, location):
+        # In cases where the source is in a subdirectory, not alongside
+        # setup.py we have to look up in the location until we find a real
+        # setup.py
+        orig_location = location
+        while not os.path.exists(os.path.join(location, 'setup.py')):
+            last_location = location
+            location = os.path.dirname(location)
+            if location == last_location:
+                # We've traversed up to the root of the filesystem without
+                # finding setup.py
+                logger.warning(
+                    "Could not find setup.py for directory %s (tried all "
+                    "parent directories)",
+                    orig_location,
+                )
+                return None
+
+        return cls._get_svn_url_rev(location)[0]
+
+    @classmethod
+    def _get_svn_url_rev(cls, location):
+        from pip._internal.exceptions import InstallationError
+
+        entries_path = os.path.join(location, cls.dirname, 'entries')
+        if os.path.exists(entries_path):
+            with open(entries_path) as f:
+                data = f.read()
+        else:  # subversion >= 1.7 does not have the 'entries' file
+            data = ''
+
+        if (data.startswith('8') or
+                data.startswith('9') or
+                data.startswith('10')):
+            data = list(map(str.splitlines, data.split('\n\x0c\n')))
+            del data[0][0]  # get rid of the '8'
+            url = data[0][3]
+            revs = [int(d[9]) for d in data if len(d) > 9 and d[9]] + [0]
+        elif data.startswith('<?xml'):
+            match = _svn_xml_url_re.search(data)
+            if not match:
+                raise ValueError('Badly formatted data: %r' % data)
+            url = match.group(1)    # get repository URL
+            revs = [int(m.group(1)) for m in _svn_rev_re.finditer(data)] + [0]
+        else:
+            try:
+                # subversion >= 1.7
+                xml = cls.run_command(
+                    ['info', '--xml', location],
+                    show_stdout=False,
+                )
+                url = _svn_info_xml_url_re.search(xml).group(1)
+                revs = [
+                    int(m.group(1)) for m in _svn_info_xml_rev_re.finditer(xml)
+                ]
+            except InstallationError:
+                url, revs = None, []
+
+        if revs:
+            rev = max(revs)
+        else:
+            rev = 0
+
+        return url, rev
+
+    @classmethod
+    def get_src_requirement(cls, location, project_name):
+        repo = cls.get_remote_url(location)
+        if repo is None:
+            return None
+        repo = 'svn+' + repo
+        rev = cls.get_revision(location)
+        return make_vcs_requirement_url(repo, rev, project_name)
+
+    def is_commit_id_equal(self, dest, name):
+        """Always assume the versions don't match"""
+        return False
+
+
+vcs.register(Subversion)
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/wheel.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/wheel.py
new file mode 100644
index 0000000..67bcc7f
--- /dev/null
+++ b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_internal/wheel.py
@@ -0,0 +1,1095 @@
+"""
+Support for installing and building the "wheel" binary package format.
+"""
+from __future__ import absolute_import
+
+import collections
+import compileall
+import csv
+import hashlib
+import logging
+import os.path
+import re
+import shutil
+import stat
+import sys
+import warnings
+from base64 import urlsafe_b64encode
+from email.parser import Parser
+
+from pip._vendor import pkg_resources
+from pip._vendor.distlib.scripts import ScriptMaker
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.six import StringIO
+
+from pip._internal import pep425tags
+from pip._internal.download import path_to_url, unpack_url
+from pip._internal.exceptions import (
+    InstallationError, InvalidWheelFilename, UnsupportedWheel,
+)
+from pip._internal.locations import (
+    PIP_DELETE_MARKER_FILENAME, distutils_scheme,
+)
+from pip._internal.models.link import Link
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    call_subprocess, captured_stdout, ensure_dir, read_chunks,
+)
+from pip._internal.utils.setuptools_build import SETUPTOOLS_SHIM
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import open_spinner
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        Dict, List, Optional, Sequence, Mapping, Tuple, IO, Text, Any,
+        Union, Iterable
+    )
+    from pip._vendor.packaging.requirements import Requirement  # noqa: F401
+    from pip._internal.req.req_install import InstallRequirement  # noqa: F401
+    from pip._internal.download import PipSession  # noqa: F401
+    from pip._internal.index import FormatControl, PackageFinder  # noqa: F401
+    from pip._internal.operations.prepare import (  # noqa: F401
+        RequirementPreparer
+    )
+    from pip._internal.cache import WheelCache  # noqa: F401
+    from pip._internal.pep425tags import Pep425Tag  # noqa: F401
+
+    InstalledCSVRow = Tuple[str, ...]
+
+
+VERSION_COMPATIBLE = (1, 0)
+
+
+logger = logging.getLogger(__name__)
+
+
+def normpath(src, p):
+    return os.path.relpath(src, p).replace(os.path.sep, '/')
+
+
+def rehash(path, blocksize=1 << 20):
+    # type: (str, int) -> Tuple[str, str]
+    """Return (hash, length) for path using hashlib.sha256()"""
+    h = hashlib.sha256()
+    length = 0
+    with open(path, 'rb') as f:
+        for block in read_chunks(f, size=blocksize):
+            length += len(block)
+            h.update(block)
+    digest = 'sha256=' + urlsafe_b64encode(
+        h.digest()
+    ).decode('latin1').rstrip('=')
+    # unicode/str python2 issues
+    return (digest, str(length))  # type: ignore
+
+
+def open_for_csv(name, mode):
+    # type: (str, Text) -> IO
+    if sys.version_info[0] < 3:
+        nl = {}  # type: Dict[str, Any]
+        bin = 'b'
+    else:
+        nl = {'newline': ''}  # type: Dict[str, Any]
+        bin = ''
+    return open(name, mode + bin, **nl)
+
+
+def replace_python_tag(wheelname, new_tag):
+    # type: (str, str) -> str
+    """Replace the Python tag in a wheel file name with a new value.
+    """
+    parts = wheelname.split('-')
+    parts[-3] = new_tag
+    return '-'.join(parts)
+
+
+def fix_script(path):
+    # type: (str) -> Optional[bool]
+    """Replace #!python with #!/path/to/python
+    Return True if file was changed."""
+    # XXX RECORD hashes will need to be updated
+    if os.path.isfile(path):
+        with open(path, 'rb') as script:
+            firstline = script.readline()
+            if not firstline.startswith(b'#!python'):
+                return False
+            exename = sys.executable.encode(sys.getfilesystemencoding())
+            firstline = b'#!' + exename + os.linesep.encode("ascii")
+            rest = script.read()
+        with open(path, 'wb') as script:
+            script.write(firstline)
+            script.write(rest)
+        return True
+    return None
+
+
+dist_info_re = re.compile(r"""^(?P<namever>(?P<name>.+?)(-(?P<ver>.+?))?)
+                                \.dist-info$""", re.VERBOSE)
+
+
+def root_is_purelib(name, wheeldir):
+    # type: (str, str) -> bool
+    """
+    Return True if the extracted wheel in wheeldir should go into purelib.
+    """
+    name_folded = name.replace("-", "_")
+    for item in os.listdir(wheeldir):
+        match = dist_info_re.match(item)
+        if match and match.group('name') == name_folded:
+            with open(os.path.join(wheeldir, item, 'WHEEL')) as wheel:
+                for line in wheel:
+                    line = line.lower().rstrip()
+                    if line == "root-is-purelib: true":
+                        return True
+    return False
+
+
+def get_entrypoints(filename):
+    # type: (str) -> Tuple[Dict[str, str], Dict[str, str]]
+    if not os.path.exists(filename):
+        return {}, {}
+
+    # This is done because you can pass a string to entry_points wrappers which
+    # means that they may or may not be valid INI files. The attempt here is to
+    # strip leading and trailing whitespace in order to make them valid INI
+    # files.
+    with open(filename) as fp:
+        data = StringIO()
+        for line in fp:
+            data.write(line.strip())
+            data.write("\n")
+        data.seek(0)
+
+    # get the entry points and then the script names
+    entry_points = pkg_resources.EntryPoint.parse_map(data)
+    console = entry_points.get('console_scripts', {})
+    gui = entry_points.get('gui_scripts', {})
+
+    def _split_ep(s):
+        """get the string representation of EntryPoint, remove space and split
+        on '='"""
+        return str(s).replace(" ", "").split("=")
+
+    # convert the EntryPoint objects into strings with module:function
+    console = dict(_split_ep(v) for v in console.values())
+    gui = dict(_split_ep(v) for v in gui.values())
+    return console, gui
+
+
+def message_about_scripts_not_on_PATH(scripts):
+    # type: (Sequence[str]) -> Optional[str]
+    """Determine if any scripts are not on PATH and format a warning.
+
+    Returns a warning message if one or more scripts are not on PATH,
+    otherwise None.
+    """
+    if not scripts:
+        return None
+
+    # Group scripts by the path they were installed in
+    grouped_by_dir = collections.defaultdict(set)  # type: Dict[str, set]
+    for destfile in scripts:
+        parent_dir = os.path.dirname(destfile)
+        script_name = os.path.basename(destfile)
+        grouped_by_dir[parent_dir].add(script_name)
+
+    # We don't want to warn for directories that are on PATH.
+    not_warn_dirs = [
+        os.path.normcase(i).rstrip(os.sep) for i in
+        os.environ.get("PATH", "").split(os.pathsep)
+    ]
+    # If an executable sits with sys.executable, we don't warn for it.
+    #     This covers the case of venv invocations without activating the venv.
+    not_warn_dirs.append(os.path.normcase(os.path.dirname(sys.executable)))
+    warn_for = {
+        parent_dir: scripts for parent_dir, scripts in grouped_by_dir.items()
+        if os.path.normcase(parent_dir) not in not_warn_dirs
+    }
+    if not warn_for:
+        return None
+
+    # Format a message
+    msg_lines = []
+    for parent_dir, scripts in warn_for.items():
+        scripts = sorted(scripts)
+        if len(scripts) == 1:
+            start_text = "script {} is".format(scripts[0])
+        else:
+            start_text = "scripts {} are".format(
+                ", ".join(scripts[:-1]) + " and " + scripts[-1]
+            )
+
+        msg_lines.append(
+            "The {} installed in '{}' which is not on PATH."
+            .format(start_text, parent_dir)
+        )
+
+    last_line_fmt = (
+        "Consider adding {} to PATH or, if you prefer "
+        "to suppress this warning, use --no-warn-script-location."
+    )
+    if len(msg_lines) == 1:
+        msg_lines.append(last_line_fmt.format("this directory"))
+    else:
+        msg_lines.append(last_line_fmt.format("these directories"))
+
+    # Returns the formatted multiline message
+    return "\n".join(msg_lines)
+
+
+def sorted_outrows(outrows):
+    # type: (Iterable[InstalledCSVRow]) -> List[InstalledCSVRow]
+    """
+    Return the given rows of a RECORD file in sorted order.
+
+    Each row is a 3-tuple (path, hash, size) and corresponds to a record of
+    a RECORD file (see PEP 376 and PEP 427 for details).  For the rows
+    passed to this function, the size can be an integer as an int or string,
+    or the empty string.
+    """
+    # Normally, there should only be one row per path, in which case the
+    # second and third elements don't come into play when sorting.
+    # However, in cases in the wild where a path might happen to occur twice,
+    # we don't want the sort operation to trigger an error (but still want
+    # determinism).  Since the third element can be an int or string, we
+    # coerce each element to a string to avoid a TypeError in this case.
+    # For additional background, see--
+    # https://github.com/pypa/pip/issues/5868
+    return sorted(outrows, key=lambda row: tuple(str(x) for x in row))
+
+
+def get_csv_rows_for_installed(
+    old_csv_rows,  # type: Iterable[List[str]]
+    installed,  # type: Dict[str, str]
+    changed,  # type: set
+    generated,  # type: List[str]
+    lib_dir,  # type: str
+):
+    # type: (...) -> List[InstalledCSVRow]
+    """
+    :param installed: A map from archive RECORD path to installation RECORD
+        path.
+    """
+    installed_rows = []  # type: List[InstalledCSVRow]
+    for row in old_csv_rows:
+        if len(row) > 3:
+            logger.warning(
+                'RECORD line has more than three elements: {}'.format(row)
+            )
+        # Make a copy because we are mutating the row.
+        row = list(row)
+        old_path = row[0]
+        new_path = installed.pop(old_path, old_path)
+        row[0] = new_path
+        if new_path in changed:
+            digest, length = rehash(new_path)
+            row[1] = digest
+            row[2] = length
+        installed_rows.append(tuple(row))
+    for f in generated:
+        digest, length = rehash(f)
+        installed_rows.append((normpath(f, lib_dir), digest, str(length)))
+    for f in installed:
+        installed_rows.append((installed[f], '', ''))
+    return installed_rows
+
+
+def move_wheel_files(
+    name,  # type: str
+    req,  # type: Requirement
+    wheeldir,  # type: str
+    user=False,  # type: bool
+    home=None,  # type: Optional[str]
+    root=None,  # type: Optional[str]
+    pycompile=True,  # type: bool
+    scheme=None,  # type: Optional[Mapping[str, str]]
+    isolated=False,  # type: bool
+    prefix=None,  # type: Optional[str]
+    warn_script_location=True  # type: bool
+):
+    # type: (...) -> None
+    """Install a wheel"""
+    # TODO: Investigate and break this up.
+    # TODO: Look into moving this into a dedicated class for representing an
+    #       installation.
+
+    if not scheme:
+        scheme = distutils_scheme(
+            name, user=user, home=home, root=root, isolated=isolated,
+            prefix=prefix,
+        )
+
+    if root_is_purelib(name, wheeldir):
+        lib_dir = scheme['purelib']
+    else:
+        lib_dir = scheme['platlib']
+
+    info_dir = []  # type: List[str]
+    data_dirs = []
+    source = wheeldir.rstrip(os.path.sep) + os.path.sep
+
+    # Record details of the files moved
+    #   installed = files copied from the wheel to the destination
+    #   changed = files changed while installing (scripts #! line typically)
+    #   generated = files newly generated during the install (script wrappers)
+    installed = {}  # type: Dict[str, str]
+    changed = set()
+    generated = []  # type: List[str]
+
+    # Compile all of the pyc files that we're going to be installing
+    if pycompile:
+        with captured_stdout() as stdout:
+            with warnings.catch_warnings():
+                warnings.filterwarnings('ignore')
+                compileall.compile_dir(source, force=True, quiet=True)
+        logger.debug(stdout.getvalue())
+
+    def record_installed(srcfile, destfile, modified=False):
+        """Map archive RECORD paths to installation RECORD paths."""
+        oldpath = normpath(srcfile, wheeldir)
+        newpath = normpath(destfile, lib_dir)
+        installed[oldpath] = newpath
+        if modified:
+            changed.add(destfile)
+
+    def clobber(source, dest, is_base, fixer=None, filter=None):
+        ensure_dir(dest)  # common for the 'include' path
+
+        for dir, subdirs, files in os.walk(source):
+            basedir = dir[len(source):].lstrip(os.path.sep)
+            destdir = os.path.join(dest, basedir)
+            if is_base and basedir.split(os.path.sep, 1)[0].endswith('.data'):
+                continue
+            for s in subdirs:
+                destsubdir = os.path.join(dest, basedir, s)
+                if is_base and basedir == '' and destsubdir.endswith('.data'):
+                    data_dirs.append(s)
+                    continue
+                elif (is_base and
+                        s.endswith('.dist-info') and
+                        canonicalize_name(s).startswith(
+                            canonicalize_name(req.name))):
+                    assert not info_dir, ('Multiple .dist-info directories: ' +
+                                          destsubdir + ', ' +
+                                          ', '.join(info_dir))
+                    info_dir.append(destsubdir)
+            for f in files:
+                # Skip unwanted files
+                if filter and filter(f):
+                    continue
+                srcfile = os.path.join(dir, f)
+                destfile = os.path.join(dest, basedir, f)
+                # directory creation is lazy and after the file filtering above
+                # to ensure we don't install empty dirs; empty dirs can't be
+                # uninstalled.
+                ensure_dir(destdir)
+
+                # copyfile (called below) truncates the destination if it
+                # exists and then writes the new contents. This is fine in most
+                # cases, but can cause a segfault if pip has loaded a shared
+                # object (e.g. from pyopenssl through its vendored urllib3)
+                # Since the shared object is mmap'd an attempt to call a
+                # symbol in it will then cause a segfault. Unlinking the file
+                # allows writing of new contents while allowing the process to
+                # continue to use the old copy.
+                if os.path.exists(destfile):
+                    os.unlink(destfile)
+
+                # We use copyfile (not move, copy, or copy2) to be extra sure
+                # that we are not moving directories over (copyfile fails for
+                # directories) as well as to ensure that we are not copying
+                # over any metadata because we want more control over what
+                # metadata we actually copy over.
+                shutil.copyfile(srcfile, destfile)
+
+                # Copy over the metadata for the file, currently this only
+                # includes the atime and mtime.
+                st = os.stat(srcfile)
+                if hasattr(os, "utime"):
+                    os.utime(destfile, (st.st_atime, st.st_mtime))
+
+                # If our file is executable, then make our destination file
+                # executable.
+                if os.access(srcfile, os.X_OK):
+                    st = os.stat(srcfile)
+                    permissions = (
+                        st.st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
+                    )
+                    os.chmod(destfile, permissions)
+
+                changed = False
+                if fixer:
+                    changed = fixer(destfile)
+                record_installed(srcfile, destfile, changed)
+
+    clobber(source, lib_dir, True)
+
+    assert info_dir, "%s .dist-info directory not found" % req
+
+    # Get the defined entry points
+    ep_file = os.path.join(info_dir[0], 'entry_points.txt')
+    console, gui = get_entrypoints(ep_file)
+
+    def is_entrypoint_wrapper(name):
+        # EP, EP.exe and EP-script.py are scripts generated for
+        # entry point EP by setuptools
+        if name.lower().endswith('.exe'):
+            matchname = name[:-4]
+        elif name.lower().endswith('-script.py'):
+            matchname = name[:-10]
+        elif name.lower().endswith(".pya"):
+            matchname = name[:-4]
+        else:
+            matchname = name
+        # Ignore setuptools-generated scripts
+        return (matchname in console or matchname in gui)
+
+    for datadir in data_dirs:
+        fixer = None
+        filter = None
+        for subdir in os.listdir(os.path.join(wheeldir, datadir)):
+            fixer = None
+            if subdir == 'scripts':
+                fixer = fix_script
+                filter = is_entrypoint_wrapper
+            source = os.path.join(wheeldir, datadir, subdir)
+            dest = scheme[subdir]
+            clobber(source, dest, False, fixer=fixer, filter=filter)
+
+    maker = ScriptMaker(None, scheme['scripts'])
+
+    # Ensure old scripts are overwritten.
+    # See https://github.com/pypa/pip/issues/1800
+    maker.clobber = True
+
+    # Ensure we don't generate any variants for scripts because this is almost
+    # never what somebody wants.
+    # See https://bitbucket.org/pypa/distlib/issue/35/
+    maker.variants = {''}
+
+    # This is required because otherwise distlib creates scripts that are not
+    # executable.
+    # See https://bitbucket.org/pypa/distlib/issue/32/
+    maker.set_mode = True
+
+    # Simplify the script and fix the fact that the default script swallows
+    # every single stack trace.
+    # See https://bitbucket.org/pypa/distlib/issue/34/
+    # See https://bitbucket.org/pypa/distlib/issue/33/
+    def _get_script_text(entry):
+        if entry.suffix is None:
+            raise InstallationError(
+                "Invalid script entry point: %s for req: %s - A callable "
+                "suffix is required. Cf https://packaging.python.org/en/"
+                "latest/distributing.html#console-scripts for more "
+                "information." % (entry, req)
+            )
+        return maker.script_template % {
+            "module": entry.prefix,
+            "import_name": entry.suffix.split(".")[0],
+            "func": entry.suffix,
+        }
+    # ignore type, because mypy disallows assigning to a method,
+    # see https://github.com/python/mypy/issues/2427
+    maker._get_script_text = _get_script_text  # type: ignore
+    maker.script_template = r"""# -*- coding: utf-8 -*-
+import re
+import sys
+
+from %(module)s import %(import_name)s
+
+if __name__ == '__main__':
+    sys.argv[0] = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv[0])
+    sys.exit(%(func)s())
+"""
+
+    # Special case pip and setuptools to generate versioned wrappers
+    #
+    # The issue is that some projects (specifically, pip and setuptools) use
+    # code in setup.py to create "versioned" entry points - pip2.7 on Python
+    # 2.7, pip3.3 on Python 3.3, etc. But these entry points are baked into
+    # the wheel metadata at build time, and so if the wheel is installed with
+    # a *different* version of Python the entry points will be wrong. The
+    # correct fix for this is to enhance the metadata to be able to describe
+    # such versioned entry points, but that won't happen till Metadata 2.0 is
+    # available.
+    # In the meantime, projects using versioned entry points will either have
+    # incorrect versioned entry points, or they will not be able to distribute
+    # "universal" wheels (i.e., they will need a wheel per Python version).
+    #
+    # Because setuptools and pip are bundled with _ensurepip and virtualenv,
+    # we need to use universal wheels. So, as a stopgap until Metadata 2.0, we
+    # override the versioned entry points in the wheel and generate the
+    # correct ones. This code is purely a short-term measure until Metadata 2.0
+    # is available.
+    #
+    # To add the level of hack in this section of code, in order to support
+    # ensurepip this code will look for an ``ENSUREPIP_OPTIONS`` environment
+    # variable which will control which version scripts get installed.
+    #
+    # ENSUREPIP_OPTIONS=altinstall
+    #   - Only pipX.Y and easy_install-X.Y will be generated and installed
+    # ENSUREPIP_OPTIONS=install
+    #   - pipX.Y, pipX, easy_install-X.Y will be generated and installed. Note
+    #     that this option is technically if ENSUREPIP_OPTIONS is set and is
+    #     not altinstall
+    # DEFAULT
+    #   - The default behavior is to install pip, pipX, pipX.Y, easy_install
+    #     and easy_install-X.Y.
+    pip_script = console.pop('pip', None)
+    if pip_script:
+        if "ENSUREPIP_OPTIONS" not in os.environ:
+            spec = 'pip = ' + pip_script
+            generated.extend(maker.make(spec))
+
+        if os.environ.get("ENSUREPIP_OPTIONS", "") != "altinstall":
+            spec = 'pip%s = %s' % (sys.version[:1], pip_script)
+            generated.extend(maker.make(spec))
+
+        spec = 'pip%s = %s' % (sys.version[:3], pip_script)
+        generated.extend(maker.make(spec))
+        # Delete any other versioned pip entry points
+        pip_ep = [k for k in console if re.match(r'pip(\d(\.\d)?)?$', k)]
+        for k in pip_ep:
+            del console[k]
+    easy_install_script = console.pop('easy_install', None)
+    if easy_install_script:
+        if "ENSUREPIP_OPTIONS" not in os.environ:
+            spec = 'easy_install = ' + easy_install_script
+            generated.extend(maker.make(spec))
+
+        spec = 'easy_install-%s = %s' % (sys.version[:3], easy_install_script)
+        generated.extend(maker.make(spec))
+        # Delete any other versioned easy_install entry points
+        easy_install_ep = [
+            k for k in console if re.match(r'easy_install(-\d\.\d)?$', k)
+        ]
+        for k in easy_install_ep:
+            del console[k]
+
+    # Generate the console and GUI entry points specified in the wheel
+    if len(console) > 0:
+        generated_console_scripts = maker.make_multiple(
+            ['%s = %s' % kv for kv in console.items()]
+        )
+        generated.extend(generated_console_scripts)
+
+        if warn_script_location:
+            msg = message_about_scripts_not_on_PATH(generated_console_scripts)
+            if msg is not None:
+                logger.warning(msg)
+
+    if len(gui) > 0:
+        generated.extend(
+            maker.make_multiple(
+                ['%s = %s' % kv for kv in gui.items()],
+                {'gui': True}
+            )
+        )
+
+    # Record pip as the installer
+    installer = os.path.join(info_dir[0], 'INSTALLER')
+    temp_installer = os.path.join(info_dir[0], 'INSTALLER.pip')
+    with open(temp_installer, 'wb') as installer_file:
+        installer_file.write(b'pip\n')
+    shutil.move(temp_installer, installer)
+    generated.append(installer)
+
+    # Record details of all files installed
+    record = os.path.join(info_dir[0], 'RECORD')
+    temp_record = os.path.join(info_dir[0], 'RECORD.pip')
+    with open_for_csv(record, 'r') as record_in:
+        with open_for_csv(temp_record, 'w+') as record_out:
+            reader = csv.reader(record_in)
+            outrows = get_csv_rows_for_installed(
+                reader, installed=installed, changed=changed,
+                generated=generated, lib_dir=lib_dir,
+            )
+            writer = csv.writer(record_out)
+            # Sort to simplify testing.
+            for row in sorted_outrows(outrows):
+                writer.writerow(row)
+    shutil.move(temp_record, record)
+
+
+def wheel_version(source_dir):
+    # type: (Optional[str]) -> Optional[Tuple[int, ...]]
+    """
+    Return the Wheel-Version of an extracted wheel, if possible.
+
+    Otherwise, return None if we couldn't parse / extract it.
+    """
+    try:
+        dist = [d for d in pkg_resources.find_on_path(None, source_dir)][0]
+
+        wheel_data = dist.get_metadata('WHEEL')
+        wheel_data = Parser().parsestr(wheel_data)
+
+        version = wheel_data['Wheel-Version'].strip()
+        version = tuple(map(int, version.split('.')))
+        return version
+    except Exception:
+        return None
+
+
+def check_compatibility(version, name):
+    # type: (Optional[Tuple[int, ...]], str) -> None
+    """
+    Raises errors or warns if called with an incompatible Wheel-Version.
+
+    Pip should refuse to install a Wheel-Version that's a major series
+    ahead of what it's compatible with (e.g 2.0 > 1.1); and warn when
+    installing a version only minor version ahead (e.g 1.2 > 1.1).
+
+    version: a 2-tuple representing a Wheel-Version (Major, Minor)
+    name: name of wheel or package to raise exception about
+
+    :raises UnsupportedWheel: when an incompatible Wheel-Version is given
+    """
+    if not version:
+        raise UnsupportedWheel(
+            "%s is in an unsupported or invalid wheel" % name
+        )
+    if version[0] > VERSION_COMPATIBLE[0]:
+        raise UnsupportedWheel(
+            "%s's Wheel-Version (%s) is not compatible with this version "
+            "of pip" % (name, '.'.join(map(str, version)))
+        )
+    elif version > VERSION_COMPATIBLE:
+        logger.warning(
+            'Installing from a newer Wheel-Version (%s)',
+            '.'.join(map(str, version)),
+        )
+
+
+class Wheel(object):
+    """A wheel file"""
+
+    # TODO: Maybe move the class into the models sub-package
+    # TODO: Maybe move the install code into this class
+
+    wheel_file_re = re.compile(
+        r"""^(?P<namever>(?P<name>.+?)-(?P<ver>.*?))
+        ((-(?P<build>\d[^-]*?))?-(?P<pyver>.+?)-(?P<abi>.+?)-(?P<plat>.+?)
+        \.whl|\.dist-info)$""",
+        re.VERBOSE
+    )
+
+    def __init__(self, filename):
+        # type: (str) -> None
+        """
+        :raises InvalidWheelFilename: when the filename is invalid for a wheel
+        """
+        wheel_info = self.wheel_file_re.match(filename)
+        if not wheel_info:
+            raise InvalidWheelFilename(
+                "%s is not a valid wheel filename." % filename
+            )
+        self.filename = filename
+        self.name = wheel_info.group('name').replace('_', '-')
+        # we'll assume "_" means "-" due to wheel naming scheme
+        # (https://github.com/pypa/pip/issues/1150)
+        self.version = wheel_info.group('ver').replace('_', '-')
+        self.build_tag = wheel_info.group('build')
+        self.pyversions = wheel_info.group('pyver').split('.')
+        self.abis = wheel_info.group('abi').split('.')
+        self.plats = wheel_info.group('plat').split('.')
+
+        # All the tag combinations from this file
+        self.file_tags = {
+            (x, y, z) for x in self.pyversions
+            for y in self.abis for z in self.plats
+        }
+
+    def support_index_min(self, tags=None):
+        # type: (Optional[List[Pep425Tag]]) -> Optional[int]
+        """
+        Return the lowest index that one of the wheel's file_tag combinations
+        achieves in the supported_tags list e.g. if there are 8 supported tags,
+        and one of the file tags is first in the list, then return 0.  Returns
+        None is the wheel is not supported.
+        """
+        if tags is None:  # for mock
+            tags = pep425tags.get_supported()
+        indexes = [tags.index(c) for c in self.file_tags if c in tags]
+        return min(indexes) if indexes else None
+
+    def supported(self, tags=None):
+        # type: (Optional[List[Pep425Tag]]) -> bool
+        """Is this wheel supported on this system?"""
+        if tags is None:  # for mock
+            tags = pep425tags.get_supported()
+        return bool(set(tags).intersection(self.file_tags))
+
+
+def _contains_egg_info(
+        s, _egg_info_re=re.compile(r'([a-z0-9_.]+)-([a-z0-9_.!+-]+)', re.I)):
+    """Determine whether the string looks like an egg_info.
+
+    :param s: The string to parse. E.g. foo-2.1
+    """
+    return bool(_egg_info_re.search(s))
+
+
+def should_use_ephemeral_cache(
+    req,  # type: InstallRequirement
+    format_control,  # type: FormatControl
+    autobuilding,  # type: bool
+    cache_available  # type: bool
+):
+    # type: (...) -> Optional[bool]
+    """
+    Return whether to build an InstallRequirement object using the
+    ephemeral cache.
+
+    :param cache_available: whether a cache directory is available for the
+        autobuilding=True case.
+
+    :return: True or False to build the requirement with ephem_cache=True
+        or False, respectively; or None not to build the requirement.
+    """
+    if req.constraint:
+        return None
+    if req.is_wheel:
+        if not autobuilding:
+            logger.info(
+                'Skipping %s, due to already being wheel.', req.name,
+            )
+        return None
+    if not autobuilding:
+        return False
+
+    if req.editable or not req.source_dir:
+        return None
+
+    if req.link and not req.link.is_artifact:
+        # VCS checkout. Build wheel just for this run.
+        return True
+
+    if "binary" not in format_control.get_allowed_formats(
+            canonicalize_name(req.name)):
+        logger.info(
+            "Skipping bdist_wheel for %s, due to binaries "
+            "being disabled for it.", req.name,
+        )
+        return None
+
+    link = req.link
+    base, ext = link.splitext()
+    if cache_available and _contains_egg_info(base):
+        return False
+
+    # Otherwise, build the wheel just for this run using the ephemeral
+    # cache since we are either in the case of e.g. a local directory, or
+    # no cache directory is available to use.
+    return True
+
+
+def format_command(
+    command_args,  # type: List[str]
+    command_output,  # type: str
+):
+    # type: (...) -> str
+    """
+    Format command information for logging.
+    """
+    text = 'Command arguments: {}\n'.format(command_args)
+
+    if not command_output:
+        text += 'Command output: None'
+    elif logger.getEffectiveLevel() > logging.DEBUG:
+        text += 'Command output: [use --verbose to show]'
+    else:
+        if not command_output.endswith('\n'):
+            command_output += '\n'
+        text += (
+            'Command output:\n{}'
+            '-----------------------------------------'
+        ).format(command_output)
+
+    return text
+
+
+def get_legacy_build_wheel_path(
+    names,  # type: List[str]
+    temp_dir,  # type: str
+    req,  # type: InstallRequirement
+    command_args,  # type: List[str]
+    command_output,  # type: str
+):
+    # type: (...) -> Optional[str]
+    """
+    Return the path to the wheel in the temporary build directory.
+    """
+    # Sort for determinism.
+    names = sorted(names)
+    if not names:
+        msg = (
+            'Legacy build of wheel for {!r} created no files.\n'
+        ).format(req.name)
+        msg += format_command(command_args, command_output)
+        logger.warning(msg)
+        return None
+
+    if len(names) > 1:
+        msg = (
+            'Legacy build of wheel for {!r} created more than one file.\n'
+            'Filenames (choosing first): {}\n'
+        ).format(req.name, names)
+        msg += format_command(command_args, command_output)
+        logger.warning(msg)
+
+    return os.path.join(temp_dir, names[0])
+
+
+class WheelBuilder(object):
+    """Build wheels from a RequirementSet."""
+
+    def __init__(
+        self,
+        finder,  # type: PackageFinder
+        preparer,  # type: RequirementPreparer
+        wheel_cache,  # type: WheelCache
+        build_options=None,  # type: Optional[List[str]]
+        global_options=None,  # type: Optional[List[str]]
+        no_clean=False  # type: bool
+    ):
+        # type: (...) -> None
+        self.finder = finder
+        self.preparer = preparer
+        self.wheel_cache = wheel_cache
+
+        self._wheel_dir = preparer.wheel_download_dir
+
+        self.build_options = build_options or []
+        self.global_options = global_options or []
+        self.no_clean = no_clean
+
+    def _build_one(self, req, output_dir, python_tag=None):
+        """Build one wheel.
+
+        :return: The filename of the built wheel, or None if the build failed.
+        """
+        # Install build deps into temporary directory (PEP 518)
+        with req.build_env:
+            return self._build_one_inside_env(req, output_dir,
+                                              python_tag=python_tag)
+
+    def _build_one_inside_env(self, req, output_dir, python_tag=None):
+        with TempDirectory(kind="wheel") as temp_dir:
+            if req.use_pep517:
+                builder = self._build_one_pep517
+            else:
+                builder = self._build_one_legacy
+            wheel_path = builder(req, temp_dir.path, python_tag=python_tag)
+            if wheel_path is not None:
+                wheel_name = os.path.basename(wheel_path)
+                dest_path = os.path.join(output_dir, wheel_name)
+                try:
+                    shutil.move(wheel_path, dest_path)
+                    logger.info('Stored in directory: %s', output_dir)
+                    return dest_path
+                except Exception:
+                    pass
+            # Ignore return, we can't do anything else useful.
+            self._clean_one(req)
+            return None
+
+    def _base_setup_args(self, req):
+        # NOTE: Eventually, we'd want to also -S to the flags here, when we're
+        # isolating. Currently, it breaks Python in virtualenvs, because it
+        # relies on site.py to find parts of the standard library outside the
+        # virtualenv.
+        return [
+            sys.executable, '-u', '-c',
+            SETUPTOOLS_SHIM % req.setup_py
+        ] + list(self.global_options)
+
+    def _build_one_pep517(self, req, tempd, python_tag=None):
+        """Build one InstallRequirement using the PEP 517 build process.
+
+        Returns path to wheel if successfully built. Otherwise, returns None.
+        """
+        assert req.metadata_directory is not None
+        try:
+            req.spin_message = 'Building wheel for %s (PEP 517)' % (req.name,)
+            logger.debug('Destination directory: %s', tempd)
+            wheel_name = req.pep517_backend.build_wheel(
+                tempd,
+                metadata_directory=req.metadata_directory
+            )
+            if python_tag:
+                # General PEP 517 backends don't necessarily support
+                # a "--python-tag" option, so we rename the wheel
+                # file directly.
+                new_name = replace_python_tag(wheel_name, python_tag)
+                os.rename(
+                    os.path.join(tempd, wheel_name),
+                    os.path.join(tempd, new_name)
+                )
+                # Reassign to simplify the return at the end of function
+                wheel_name = new_name
+        except Exception:
+            logger.error('Failed building wheel for %s', req.name)
+            return None
+        return os.path.join(tempd, wheel_name)
+
+    def _build_one_legacy(self, req, tempd, python_tag=None):
+        """Build one InstallRequirement using the "legacy" build process.
+
+        Returns path to wheel if successfully built. Otherwise, returns None.
+        """
+        base_args = self._base_setup_args(req)
+
+        spin_message = 'Building wheel for %s (setup.py)' % (req.name,)
+        with open_spinner(spin_message) as spinner:
+            logger.debug('Destination directory: %s', tempd)
+            wheel_args = base_args + ['bdist_wheel', '-d', tempd] \
+                + self.build_options
+
+            if python_tag is not None:
+                wheel_args += ["--python-tag", python_tag]
+
+            try:
+                output = call_subprocess(wheel_args, cwd=req.setup_py_dir,
+                                         show_stdout=False, spinner=spinner)
+            except Exception:
+                spinner.finish("error")
+                logger.error('Failed building wheel for %s', req.name)
+                return None
+            names = os.listdir(tempd)
+            wheel_path = get_legacy_build_wheel_path(
+                names=names,
+                temp_dir=tempd,
+                req=req,
+                command_args=wheel_args,
+                command_output=output,
+            )
+            return wheel_path
+
+    def _clean_one(self, req):
+        base_args = self._base_setup_args(req)
+
+        logger.info('Running setup.py clean for %s', req.name)
+        clean_args = base_args + ['clean', '--all']
+        try:
+            call_subprocess(clean_args, cwd=req.source_dir, show_stdout=False)
+            return True
+        except Exception:
+            logger.error('Failed cleaning build dir for %s', req.name)
+            return False
+
+    def build(
+        self,
+        requirements,  # type: Iterable[InstallRequirement]
+        session,  # type: PipSession
+        autobuilding=False  # type: bool
+    ):
+        # type: (...) -> List[InstallRequirement]
+        """Build wheels.
+
+        :param unpack: If True, replace the sdist we built from with the
+            newly built wheel, in preparation for installation.
+        :return: True if all the wheels built correctly.
+        """
+        buildset = []
+        format_control = self.finder.format_control
+        # Whether a cache directory is available for autobuilding=True.
+        cache_available = bool(self._wheel_dir or self.wheel_cache.cache_dir)
+
+        for req in requirements:
+            ephem_cache = should_use_ephemeral_cache(
+                req, format_control=format_control, autobuilding=autobuilding,
+                cache_available=cache_available,
+            )
+            if ephem_cache is None:
+                continue
+
+            buildset.append((req, ephem_cache))
+
+        if not buildset:
+            return []
+
+        # Is any wheel build not using the ephemeral cache?
+        if any(not ephem_cache for _, ephem_cache in buildset):
+            have_directory_for_build = self._wheel_dir or (
+                autobuilding and self.wheel_cache.cache_dir
+            )
+            assert have_directory_for_build
+
+        # TODO by @pradyunsg
+        # Should break up this method into 2 separate methods.
+
+        # Build the wheels.
+        logger.info(
+            'Building wheels for collected packages: %s',
+            ', '.join([req.name for (req, _) in buildset]),
+        )
+        _cache = self.wheel_cache  # shorter name
+        with indent_log():
+            build_success, build_failure = [], []
+            for req, ephem in buildset:
+                python_tag = None
+                if autobuilding:
+                    python_tag = pep425tags.implementation_tag
+                    if ephem:
+                        output_dir = _cache.get_ephem_path_for_link(req.link)
+                    else:
+                        output_dir = _cache.get_path_for_link(req.link)
+                    try:
+                        ensure_dir(output_dir)
+                    except OSError as e:
+                        logger.warning("Building wheel for %s failed: %s",
+                                       req.name, e)
+                        build_failure.append(req)
+                        continue
+                else:
+                    output_dir = self._wheel_dir
+                wheel_file = self._build_one(
+                    req, output_dir,
+                    python_tag=python_tag,
+                )
+                if wheel_file:
+                    build_success.append(req)
+                    if autobuilding:
+                        # XXX: This is mildly duplicative with prepare_files,
+                        # but not close enough to pull out to a single common
+                        # method.
+                        # The code below assumes temporary source dirs -
+                        # prevent it doing bad things.
+                        if req.source_dir and not os.path.exists(os.path.join(
+                                req.source_dir, PIP_DELETE_MARKER_FILENAME)):
+                            raise AssertionError(
+                                "bad source dir - missing marker")
+                        # Delete the source we built the wheel from
+                        req.remove_temporary_source()
+                        # set the build directory again - name is known from
+                        # the work prepare_files did.
+                        req.source_dir = req.build_location(
+                            self.preparer.build_dir
+                        )
+                        # Update the link for this.
+                        req.link = Link(path_to_url(wheel_file))
+                        assert req.link.is_wheel
+                        # extract the wheel into the dir
+                        unpack_url(
+                            req.link, req.source_dir, None, False,
+                            session=session,
+                        )
+                else:
+                    build_failure.append(req)
+
+        # notify success/failure
+        if build_success:
+            logger.info(
+                'Successfully built %s',
+                ' '.join([req.name for req in build_success]),
+            )
+        if build_failure:
+            logger.info(
+                'Failed to build %s',
+                ' '.join([req.name for req in build_failure]),
+            )
+        # Return a list of requirements that failed to build
+        return build_failure