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Diffstat (limited to 'venv/Lib/site-packages/astroid/scoped_nodes.py')
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diff --git a/venv/Lib/site-packages/astroid/scoped_nodes.py b/venv/Lib/site-packages/astroid/scoped_nodes.py new file mode 100644 index 0000000..d02b653 --- /dev/null +++ b/venv/Lib/site-packages/astroid/scoped_nodes.py @@ -0,0 +1,2836 @@ +# -*- coding: utf-8 -*- +# Copyright (c) 2006-2014 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr> +# Copyright (c) 2010 Daniel Harding <dharding@gmail.com> +# Copyright (c) 2011, 2013-2015 Google, Inc. +# Copyright (c) 2013-2018 Claudiu Popa <pcmanticore@gmail.com> +# Copyright (c) 2013 Phil Schaf <flying-sheep@web.de> +# Copyright (c) 2014 Eevee (Alex Munroe) <amunroe@yelp.com> +# Copyright (c) 2015-2016 Florian Bruhin <me@the-compiler.org> +# Copyright (c) 2015-2016 Ceridwen <ceridwenv@gmail.com> +# Copyright (c) 2015 Rene Zhang <rz99@cornell.edu> +# Copyright (c) 2015 Philip Lorenz <philip@bithub.de> +# Copyright (c) 2016-2017 Derek Gustafson <degustaf@gmail.com> +# Copyright (c) 2017-2018 Bryce Guinta <bryce.paul.guinta@gmail.com> +# Copyright (c) 2017-2018 Ashley Whetter <ashley@awhetter.co.uk> +# Copyright (c) 2017 Łukasz Rogalski <rogalski.91@gmail.com> +# Copyright (c) 2017 David Euresti <david@dropbox.com> +# Copyright (c) 2018 Nick Drozd <nicholasdrozd@gmail.com> +# Copyright (c) 2018 Anthony Sottile <asottile@umich.edu> +# Copyright (c) 2018 HoverHell <hoverhell@gmail.com> + +# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html +# For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER + + +""" +This module contains the classes for "scoped" node, i.e. which are opening a +new local scope in the language definition : Module, ClassDef, FunctionDef (and +Lambda, GeneratorExp, DictComp and SetComp to some extent). +""" + +import builtins +import sys +import io +import itertools +from typing import Optional, List + +from astroid import bases +from astroid import context as contextmod +from astroid import exceptions +from astroid import decorators as decorators_mod +from astroid.interpreter import objectmodel +from astroid.interpreter import dunder_lookup +from astroid import manager +from astroid import mixins +from astroid import node_classes +from astroid import util + + +BUILTINS = builtins.__name__ +ITER_METHODS = ("__iter__", "__getitem__") +EXCEPTION_BASE_CLASSES = frozenset({"Exception", "BaseException"}) +objects = util.lazy_import("objects") + + +def _c3_merge(sequences, cls, context): + """Merges MROs in *sequences* to a single MRO using the C3 algorithm. + + Adapted from http://www.python.org/download/releases/2.3/mro/. + + """ + result = [] + while True: + sequences = [s for s in sequences if s] # purge empty sequences + if not sequences: + return result + for s1 in sequences: # find merge candidates among seq heads + candidate = s1[0] + for s2 in sequences: + if candidate in s2[1:]: + candidate = None + break # reject the current head, it appears later + else: + break + if not candidate: + # Show all the remaining bases, which were considered as + # candidates for the next mro sequence. + raise exceptions.InconsistentMroError( + message="Cannot create a consistent method resolution order " + "for MROs {mros} of class {cls!r}.", + mros=sequences, + cls=cls, + context=context, + ) + + result.append(candidate) + # remove the chosen candidate + for seq in sequences: + if seq[0] == candidate: + del seq[0] + return None + + +def clean_duplicates_mro(sequences, cls, context): + for sequence in sequences: + names = [ + (node.lineno, node.qname()) if node.name else None for node in sequence + ] + last_index = dict(map(reversed, enumerate(names))) + if names and names[0] is not None and last_index[names[0]] != 0: + raise exceptions.DuplicateBasesError( + message="Duplicates found in MROs {mros} for {cls!r}.", + mros=sequences, + cls=cls, + context=context, + ) + yield [ + node + for i, (node, name) in enumerate(zip(sequence, names)) + if name is None or last_index[name] == i + ] + + +def function_to_method(n, klass): + if isinstance(n, FunctionDef): + if n.type == "classmethod": + return bases.BoundMethod(n, klass) + if n.type != "staticmethod": + return bases.UnboundMethod(n) + return n + + +MANAGER = manager.AstroidManager() + + +def builtin_lookup(name): + """lookup a name into the builtin module + return the list of matching statements and the astroid for the builtin + module + """ + builtin_astroid = MANAGER.ast_from_module(builtins) + if name == "__dict__": + return builtin_astroid, () + try: + stmts = builtin_astroid.locals[name] + except KeyError: + stmts = () + return builtin_astroid, stmts + + +# TODO move this Mixin to mixins.py; problem: 'FunctionDef' in _scope_lookup +class LocalsDictNodeNG(node_classes.LookupMixIn, node_classes.NodeNG): + """ this class provides locals handling common to Module, FunctionDef + and ClassDef nodes, including a dict like interface for direct access + to locals information + """ + + # attributes below are set by the builder module or by raw factories + + locals = {} + """A map of the name of a local variable to the node defining the local. + + :type: dict(str, NodeNG) + """ + + def qname(self): + """Get the 'qualified' name of the node. + + For example: module.name, module.class.name ... + + :returns: The qualified name. + :rtype: str + """ + # pylint: disable=no-member; github.com/pycqa/astroid/issues/278 + if self.parent is None: + return self.name + return "%s.%s" % (self.parent.frame().qname(), self.name) + + def frame(self): + """The first parent frame node. + + A frame node is a :class:`Module`, :class:`FunctionDef`, + or :class:`ClassDef`. + + :returns: The first parent frame node. + :rtype: Module or FunctionDef or ClassDef + """ + return self + + def scope(self): + """The first parent node defining a new scope. + + :returns: The first parent scope node. + :rtype: Module or FunctionDef or ClassDef or Lambda or GenExpr + """ + return self + + def _scope_lookup(self, node, name, offset=0): + """XXX method for interfacing the scope lookup""" + try: + stmts = node._filter_stmts(self.locals[name], self, offset) + except KeyError: + stmts = () + if stmts: + return self, stmts + if self.parent: # i.e. not Module + # nested scope: if parent scope is a function, that's fine + # else jump to the module + pscope = self.parent.scope() + if not pscope.is_function: + pscope = pscope.root() + return pscope.scope_lookup(node, name) + return builtin_lookup(name) # Module + + def set_local(self, name, stmt): + """Define that the given name is declared in the given statement node. + + .. seealso:: :meth:`scope` + + :param name: The name that is being defined. + :type name: str + + :param stmt: The statement that defines the given name. + :type stmt: NodeNG + """ + # assert not stmt in self.locals.get(name, ()), (self, stmt) + self.locals.setdefault(name, []).append(stmt) + + __setitem__ = set_local + + def _append_node(self, child): + """append a child, linking it in the tree""" + # pylint: disable=no-member; depending by the class + # which uses the current class as a mixin or base class. + # It's rewritten in 2.0, so it makes no sense for now + # to spend development time on it. + self.body.append(child) + child.parent = self + + def add_local_node(self, child_node, name=None): + """Append a child that should alter the locals of this scope node. + + :param child_node: The child node that will alter locals. + :type child_node: NodeNG + + :param name: The name of the local that will be altered by + the given child node. + :type name: str or None + """ + if name != "__class__": + # add __class__ node as a child will cause infinite recursion later! + self._append_node(child_node) + self.set_local(name or child_node.name, child_node) + + def __getitem__(self, item): + """The first node the defines the given local. + + :param item: The name of the locally defined object. + :type item: str + + :raises KeyError: If the name is not defined. + """ + return self.locals[item][0] + + def __iter__(self): + """Iterate over the names of locals defined in this scoped node. + + :returns: The names of the defined locals. + :rtype: iterable(str) + """ + return iter(self.keys()) + + def keys(self): + """The names of locals defined in this scoped node. + + :returns: The names of the defined locals. + :rtype: list(str) + """ + return list(self.locals.keys()) + + def values(self): + """The nodes that define the locals in this scoped node. + + :returns: The nodes that define locals. + :rtype: list(NodeNG) + """ + return [self[key] for key in self.keys()] + + def items(self): + """Get the names of the locals and the node that defines the local. + + :returns: The names of locals and their associated node. + :rtype: list(tuple(str, NodeNG)) + """ + return list(zip(self.keys(), self.values())) + + def __contains__(self, name): + """Check if a local is defined in this scope. + + :param name: The name of the local to check for. + :type name: str + + :returns: True if this node has a local of the given name, + False otherwise. + :rtype: bool + """ + return name in self.locals + + +class Module(LocalsDictNodeNG): + """Class representing an :class:`ast.Module` node. + + >>> node = astroid.extract_node('import astroid') + >>> node + <Import l.1 at 0x7f23b2e4e5c0> + >>> node.parent + <Module l.0 at 0x7f23b2e4eda0> + """ + + _astroid_fields = ("body",) + + fromlineno = 0 + """The first line that this node appears on in the source code. + + :type: int or None + """ + lineno = 0 + """The line that this node appears on in the source code. + + :type: int or None + """ + + # attributes below are set by the builder module or by raw factories + + file = None + """The path to the file that this ast has been extracted from. + + This will be ``None`` when the representation has been built from a + built-in module. + + :type: str or None + """ + file_bytes = None + """The string/bytes that this ast was built from. + + :type: str or bytes or None + """ + file_encoding = None + """The encoding of the source file. + + This is used to get unicode out of a source file. + Python 2 only. + + :type: str or None + """ + name = None + """The name of the module. + + :type: str or None + """ + pure_python = None + """Whether the ast was built from source. + + :type: bool or None + """ + package = None + """Whether the node represents a package or a module. + + :type: bool or None + """ + globals = None + """A map of the name of a global variable to the node defining the global. + + :type: dict(str, NodeNG) + """ + + # Future imports + future_imports = None + """The imports from ``__future__``. + + :type: set(str) or None + """ + special_attributes = objectmodel.ModuleModel() + """The names of special attributes that this module has. + + :type: objectmodel.ModuleModel + """ + + # names of module attributes available through the global scope + scope_attrs = {"__name__", "__doc__", "__file__", "__path__", "__package__"} + """The names of module attributes available through the global scope. + + :type: str(str) + """ + + _other_fields = ( + "name", + "doc", + "file", + "path", + "package", + "pure_python", + "future_imports", + ) + _other_other_fields = ("locals", "globals") + + def __init__( + self, + name, + doc, + file=None, + path: Optional[List[str]] = None, + package=None, + parent=None, + pure_python=True, + ): + """ + :param name: The name of the module. + :type name: str + + :param doc: The module docstring. + :type doc: str + + :param file: The path to the file that this ast has been extracted from. + :type file: str or None + + :param path: + :type path: Optional[List[str]] + + :param package: Whether the node represents a package or a module. + :type package: bool or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + + :param pure_python: Whether the ast was built from source. + :type pure_python: bool or None + """ + self.name = name + self.doc = doc + self.file = file + self.path = path + self.package = package + self.parent = parent + self.pure_python = pure_python + self.locals = self.globals = {} + """A map of the name of a local variable to the node defining the local. + + :type: dict(str, NodeNG) + """ + self.body = [] + """The contents of the module. + + :type: list(NodeNG) or None + """ + self.future_imports = set() + + # pylint: enable=redefined-builtin + + def postinit(self, body=None): + """Do some setup after initialisation. + + :param body: The contents of the module. + :type body: list(NodeNG) or None + """ + self.body = body + + def _get_stream(self): + if self.file_bytes is not None: + return io.BytesIO(self.file_bytes) + if self.file is not None: + stream = open(self.file, "rb") + return stream + return None + + def stream(self): + """Get a stream to the underlying file or bytes. + + :type: file or io.BytesIO or None + """ + return self._get_stream() + + def block_range(self, lineno): + """Get a range from where this node starts to where this node ends. + + :param lineno: Unused. + :type lineno: int + + :returns: The range of line numbers that this node belongs to. + :rtype: tuple(int, int) + """ + return self.fromlineno, self.tolineno + + def scope_lookup(self, node, name, offset=0): + """Lookup where the given variable is assigned. + + :param node: The node to look for assignments up to. + Any assignments after the given node are ignored. + :type node: NodeNG + + :param name: The name of the variable to find assignments for. + :type name: str + + :param offset: The line offset to filter statements up to. + :type offset: int + + :returns: This scope node and the list of assignments associated to the + given name according to the scope where it has been found (locals, + globals or builtin). + :rtype: tuple(str, list(NodeNG)) + """ + if name in self.scope_attrs and name not in self.locals: + try: + return self, self.getattr(name) + except exceptions.AttributeInferenceError: + return self, () + return self._scope_lookup(node, name, offset) + + def pytype(self): + """Get the name of the type that this node represents. + + :returns: The name of the type. + :rtype: str + """ + return "%s.module" % BUILTINS + + def display_type(self): + """A human readable type of this node. + + :returns: The type of this node. + :rtype: str + """ + return "Module" + + def getattr(self, name, context=None, ignore_locals=False): + result = [] + name_in_locals = name in self.locals + + if name in self.special_attributes and not ignore_locals and not name_in_locals: + result = [self.special_attributes.lookup(name)] + elif not ignore_locals and name_in_locals: + result = self.locals[name] + elif self.package: + try: + result = [self.import_module(name, relative_only=True)] + except (exceptions.AstroidBuildingError, SyntaxError) as exc: + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) from exc + result = [n for n in result if not isinstance(n, node_classes.DelName)] + if result: + return result + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) + + def igetattr(self, name, context=None): + """Infer the possible values of the given variable. + + :param name: The name of the variable to infer. + :type name: str + + :returns: The inferred possible values. + :rtype: iterable(NodeNG) or None + """ + # set lookup name since this is necessary to infer on import nodes for + # instance + context = contextmod.copy_context(context) + context.lookupname = name + try: + return bases._infer_stmts(self.getattr(name, context), context, frame=self) + except exceptions.AttributeInferenceError as error: + raise exceptions.InferenceError( + error.message, target=self, attribute=name, context=context + ) from error + + def fully_defined(self): + """Check if this module has been build from a .py file. + + If so, the module contains a complete representation, + including the code. + + :returns: True if the module has been built from a .py file. + :rtype: bool + """ + return self.file is not None and self.file.endswith(".py") + + def statement(self): + """The first parent node, including self, marked as statement node. + + :returns: The first parent statement. + :rtype: NodeNG + """ + return self + + def previous_sibling(self): + """The previous sibling statement. + + :returns: The previous sibling statement node. + :rtype: NodeNG or None + """ + + def next_sibling(self): + """The next sibling statement node. + + :returns: The next sibling statement node. + :rtype: NodeNG or None + """ + + _absolute_import_activated = True + + def absolute_import_activated(self): + """Whether :pep:`328` absolute import behaviour has been enabled. + + :returns: True if :pep:`328` has been enabled, False otherwise. + :rtype: bool + """ + return self._absolute_import_activated + + def import_module(self, modname, relative_only=False, level=None): + """Get the ast for a given module as if imported from this module. + + :param modname: The name of the module to "import". + :type modname: str + + :param relative_only: Whether to only consider relative imports. + :type relative_only: bool + + :param level: The level of relative import. + :type level: int or None + + :returns: The imported module ast. + :rtype: NodeNG + """ + if relative_only and level is None: + level = 0 + absmodname = self.relative_to_absolute_name(modname, level) + + try: + return MANAGER.ast_from_module_name(absmodname) + except exceptions.AstroidBuildingError: + # we only want to import a sub module or package of this module, + # skip here + if relative_only: + raise + return MANAGER.ast_from_module_name(modname) + + def relative_to_absolute_name(self, modname, level): + """Get the absolute module name for a relative import. + + The relative import can be implicit or explicit. + + :param modname: The module name to convert. + :type modname: str + + :param level: The level of relative import. + :type level: int + + :returns: The absolute module name. + :rtype: str + + :raises TooManyLevelsError: When the relative import refers to a + module too far above this one. + """ + # XXX this returns non sens when called on an absolute import + # like 'pylint.checkers.astroid.utils' + # XXX doesn't return absolute name if self.name isn't absolute name + if self.absolute_import_activated() and level is None: + return modname + if level: + if self.package: + level = level - 1 + if level and self.name.count(".") < level: + raise exceptions.TooManyLevelsError(level=level, name=self.name) + + package_name = self.name.rsplit(".", level)[0] + elif self.package: + package_name = self.name + else: + package_name = self.name.rsplit(".", 1)[0] + + if package_name: + if not modname: + return package_name + return "%s.%s" % (package_name, modname) + return modname + + def wildcard_import_names(self): + """The list of imported names when this module is 'wildcard imported'. + + It doesn't include the '__builtins__' name which is added by the + current CPython implementation of wildcard imports. + + :returns: The list of imported names. + :rtype: list(str) + """ + # We separate the different steps of lookup in try/excepts + # to avoid catching too many Exceptions + default = [name for name in self.keys() if not name.startswith("_")] + try: + all_values = self["__all__"] + except KeyError: + return default + + try: + explicit = next(all_values.assigned_stmts()) + except exceptions.InferenceError: + return default + except AttributeError: + # not an assignment node + # XXX infer? + return default + + # Try our best to detect the exported name. + inferred = [] + try: + explicit = next(explicit.infer()) + except exceptions.InferenceError: + return default + if not isinstance(explicit, (node_classes.Tuple, node_classes.List)): + return default + + str_const = lambda node: ( + isinstance(node, node_classes.Const) and isinstance(node.value, str) + ) + for node in explicit.elts: + if str_const(node): + inferred.append(node.value) + else: + try: + inferred_node = next(node.infer()) + except exceptions.InferenceError: + continue + if str_const(inferred_node): + inferred.append(inferred_node.value) + return inferred + + def public_names(self): + """The list of the names that are publicly available in this module. + + :returns: The list of publc names. + :rtype: list(str) + """ + return [name for name in self.keys() if not name.startswith("_")] + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`Module` this is always ``True``. + :rtype: bool + """ + return True + + def get_children(self): + yield from self.body + + +class ComprehensionScope(LocalsDictNodeNG): + """Scoping for different types of comprehensions.""" + + def frame(self): + """The first parent frame node. + + A frame node is a :class:`Module`, :class:`FunctionDef`, + or :class:`ClassDef`. + + :returns: The first parent frame node. + :rtype: Module or FunctionDef or ClassDef + """ + return self.parent.frame() + + scope_lookup = LocalsDictNodeNG._scope_lookup + + +class GeneratorExp(ComprehensionScope): + """Class representing an :class:`ast.GeneratorExp` node. + + >>> node = astroid.extract_node('(thing for thing in things if thing)') + >>> node + <GeneratorExp l.1 at 0x7f23b2e4e400> + """ + + _astroid_fields = ("elt", "generators") + _other_other_fields = ("locals",) + elt = None + """The element that forms the output of the expression. + + :type: NodeNG or None + """ + generators = None + """The generators that are looped through. + + :type: list(Comprehension) or None + """ + + def __init__(self, lineno=None, col_offset=None, parent=None): + """ + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.locals = {} + """A map of the name of a local variable to the node defining the local. + + :type: dict(str, NodeNG) + """ + + super(GeneratorExp, self).__init__(lineno, col_offset, parent) + + def postinit(self, elt=None, generators=None): + """Do some setup after initialisation. + + :param elt: The element that forms the output of the expression. + :type elt: NodeNG or None + + :param generators: The generators that are looped through. + :type generators: list(Comprehension) or None + """ + self.elt = elt + if generators is None: + self.generators = [] + else: + self.generators = generators + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`GeneratorExp` this is always ``True``. + :rtype: bool + """ + return True + + def get_children(self): + yield self.elt + + yield from self.generators + + +class DictComp(ComprehensionScope): + """Class representing an :class:`ast.DictComp` node. + + >>> node = astroid.extract_node('{k:v for k, v in things if k > v}') + >>> node + <DictComp l.1 at 0x7f23b2e41d68> + """ + + _astroid_fields = ("key", "value", "generators") + _other_other_fields = ("locals",) + key = None + """What produces the keys. + + :type: NodeNG or None + """ + value = None + """What produces the values. + + :type: NodeNG or None + """ + generators = None + """The generators that are looped through. + + :type: list(Comprehension) or None + """ + + def __init__(self, lineno=None, col_offset=None, parent=None): + """ + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.locals = {} + """A map of the name of a local variable to the node defining the local. + + :type: dict(str, NodeNG) + """ + + super(DictComp, self).__init__(lineno, col_offset, parent) + + def postinit(self, key=None, value=None, generators=None): + """Do some setup after initialisation. + + :param key: What produces the keys. + :type key: NodeNG or None + + :param value: What produces the values. + :type value: NodeNG or None + + :param generators: The generators that are looped through. + :type generators: list(Comprehension) or None + """ + self.key = key + self.value = value + if generators is None: + self.generators = [] + else: + self.generators = generators + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`DictComp` this is always :class:`Uninferable`. + :rtype: Uninferable + """ + return util.Uninferable + + def get_children(self): + yield self.key + yield self.value + + yield from self.generators + + +class SetComp(ComprehensionScope): + """Class representing an :class:`ast.SetComp` node. + + >>> node = astroid.extract_node('{thing for thing in things if thing}') + >>> node + <SetComp l.1 at 0x7f23b2e41898> + """ + + _astroid_fields = ("elt", "generators") + _other_other_fields = ("locals",) + elt = None + """The element that forms the output of the expression. + + :type: NodeNG or None + """ + generators = None + """The generators that are looped through. + + :type: list(Comprehension) or None + """ + + def __init__(self, lineno=None, col_offset=None, parent=None): + """ + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.locals = {} + """A map of the name of a local variable to the node defining the local. + + :type: dict(str, NodeNG) + """ + + super(SetComp, self).__init__(lineno, col_offset, parent) + + def postinit(self, elt=None, generators=None): + """Do some setup after initialisation. + + :param elt: The element that forms the output of the expression. + :type elt: NodeNG or None + + :param generators: The generators that are looped through. + :type generators: list(Comprehension) or None + """ + self.elt = elt + if generators is None: + self.generators = [] + else: + self.generators = generators + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`SetComp` this is always :class:`Uninferable`. + :rtype: Uninferable + """ + return util.Uninferable + + def get_children(self): + yield self.elt + + yield from self.generators + + +class _ListComp(node_classes.NodeNG): + """Class representing an :class:`ast.ListComp` node. + + >>> node = astroid.extract_node('[thing for thing in things if thing]') + >>> node + <ListComp l.1 at 0x7f23b2e418d0> + """ + + _astroid_fields = ("elt", "generators") + elt = None + """The element that forms the output of the expression. + + :type: NodeNG or None + """ + generators = None + """The generators that are looped through. + + :type: list(Comprehension) or None + """ + + def postinit(self, elt=None, generators=None): + """Do some setup after initialisation. + + :param elt: The element that forms the output of the expression. + :type elt: NodeNG or None + + :param generators: The generators that are looped through. + :type generators: list(Comprehension) or None + """ + self.elt = elt + self.generators = generators + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`ListComp` this is always :class:`Uninferable`. + :rtype: Uninferable + """ + return util.Uninferable + + def get_children(self): + yield self.elt + + yield from self.generators + + +class ListComp(_ListComp, ComprehensionScope): + """Class representing an :class:`ast.ListComp` node. + + >>> node = astroid.extract_node('[thing for thing in things if thing]') + >>> node + <ListComp l.1 at 0x7f23b2e418d0> + """ + + _other_other_fields = ("locals",) + + def __init__(self, lineno=None, col_offset=None, parent=None): + self.locals = {} + """A map of the name of a local variable to the node defining it. + + :type: dict(str, NodeNG) + """ + + super(ListComp, self).__init__(lineno, col_offset, parent) + + +def _infer_decorator_callchain(node): + """Detect decorator call chaining and see if the end result is a + static or a classmethod. + """ + if not isinstance(node, FunctionDef): + return None + if not node.parent: + return None + try: + result = next(node.infer_call_result(node.parent)) + except exceptions.InferenceError: + return None + if isinstance(result, bases.Instance): + result = result._proxied + if isinstance(result, ClassDef): + if result.is_subtype_of("%s.classmethod" % BUILTINS): + return "classmethod" + if result.is_subtype_of("%s.staticmethod" % BUILTINS): + return "staticmethod" + return None + + +class Lambda(mixins.FilterStmtsMixin, LocalsDictNodeNG): + """Class representing an :class:`ast.Lambda` node. + + >>> node = astroid.extract_node('lambda arg: arg + 1') + >>> node + <Lambda.<lambda> l.1 at 0x7f23b2e41518> + """ + + _astroid_fields = ("args", "body") + _other_other_fields = ("locals",) + name = "<lambda>" + is_lambda = True + + def implicit_parameters(self): + return 0 + + # function's type, 'function' | 'method' | 'staticmethod' | 'classmethod' + @property + def type(self): + """Whether this is a method or function. + + :returns: 'method' if this is a method, 'function' otherwise. + :rtype: str + """ + # pylint: disable=no-member + if self.args.args and self.args.args[0].name == "self": + if isinstance(self.parent.scope(), ClassDef): + return "method" + return "function" + + def __init__(self, lineno=None, col_offset=None, parent=None): + """ + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.locals = {} + """A map of the name of a local variable to the node defining it. + + :type: dict(str, NodeNG) + """ + + self.args = [] + """The arguments that the function takes. + + :type: Arguments or list + """ + + self.body = [] + """The contents of the function body. + + :type: list(NodeNG) + """ + + super(Lambda, self).__init__(lineno, col_offset, parent) + + def postinit(self, args, body): + """Do some setup after initialisation. + + :param args: The arguments that the function takes. + :type args: Arguments + + :param body: The contents of the function body. + :type body: list(NodeNG) + """ + self.args = args + self.body = body + + def pytype(self): + """Get the name of the type that this node represents. + + :returns: The name of the type. + :rtype: str + """ + if "method" in self.type: + return "%s.instancemethod" % BUILTINS + return "%s.function" % BUILTINS + + def display_type(self): + """A human readable type of this node. + + :returns: The type of this node. + :rtype: str + """ + if "method" in self.type: + return "Method" + return "Function" + + def callable(self): + """Whether this node defines something that is callable. + + :returns: True if this defines something that is callable, + False otherwise. + For a :class:`Lambda` this is always ``True``. + :rtype: bool + """ + return True + + def argnames(self): + """Get the names of each of the arguments. + + :returns: The names of the arguments. + :rtype: list(str) + """ + # pylint: disable=no-member; github.com/pycqa/astroid/issues/291 + # args is in fact redefined later on by postinit. Can't be changed + # to None due to a strong interaction between Lambda and FunctionDef. + + if self.args.args: # maybe None with builtin functions + names = _rec_get_names(self.args.args) + else: + names = [] + if self.args.vararg: + names.append(self.args.vararg) + if self.args.kwarg: + names.append(self.args.kwarg) + return names + + def infer_call_result(self, caller, context=None): + """Infer what the function returns when called. + + :param caller: Unused + :type caller: object + """ + # pylint: disable=no-member; github.com/pycqa/astroid/issues/291 + # args is in fact redefined later on by postinit. Can't be changed + # to None due to a strong interaction between Lambda and FunctionDef. + return self.body.infer(context) + + def scope_lookup(self, node, name, offset=0): + """Lookup where the given names is assigned. + + :param node: The node to look for assignments up to. + Any assignments after the given node are ignored. + :type node: NodeNG + + :param name: The name to find assignments for. + :type name: str + + :param offset: The line offset to filter statements up to. + :type offset: int + + :returns: This scope node and the list of assignments associated to the + given name according to the scope where it has been found (locals, + globals or builtin). + :rtype: tuple(str, list(NodeNG)) + """ + # pylint: disable=no-member; github.com/pycqa/astroid/issues/291 + # args is in fact redefined later on by postinit. Can't be changed + # to None due to a strong interaction between Lambda and FunctionDef. + + if node in self.args.defaults or node in self.args.kw_defaults: + frame = self.parent.frame() + # line offset to avoid that def func(f=func) resolve the default + # value to the defined function + offset = -1 + else: + # check this is not used in function decorators + frame = self + return frame._scope_lookup(node, name, offset) + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`Lambda` this is always ``True``. + :rtype: bool + """ + return True + + def get_children(self): + yield self.args + yield self.body + + +class FunctionDef(mixins.MultiLineBlockMixin, node_classes.Statement, Lambda): + """Class representing an :class:`ast.FunctionDef`. + + >>> node = astroid.extract_node(''' + ... def my_func(arg): + ... return arg + 1 + ... ''') + >>> node + <FunctionDef.my_func l.2 at 0x7f23b2e71e10> + """ + + _astroid_fields = ("decorators", "args", "returns", "body") + _multi_line_block_fields = ("body",) + returns = None + decorators = None + """The decorators that are applied to this method or function. + + :type: Decorators or None + """ + special_attributes = objectmodel.FunctionModel() + """The names of special attributes that this function has. + + :type: objectmodel.FunctionModel + """ + is_function = True + """Whether this node indicates a function. + + For a :class:`FunctionDef` this is always ``True``. + + :type: bool + """ + type_annotation = None + """If present, this will contain the type annotation passed by a type comment + + :type: NodeNG or None + """ + type_comment_args = None + """ + If present, this will contain the type annotation for arguments + passed by a type comment + """ + type_comment_returns = None + """If present, this will contain the return type annotation, passed by a type comment""" + # attributes below are set by the builder module or by raw factories + _other_fields = ("name", "doc") + _other_other_fields = ( + "locals", + "_type", + "type_comment_returns", + "type_comment_args", + ) + _type = None + + def __init__(self, name=None, doc=None, lineno=None, col_offset=None, parent=None): + """ + :param name: The name of the function. + :type name: str or None + + :param doc: The function's docstring. + :type doc: str or None + + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.name = name + """The name of the function. + + :type name: str or None + """ + + self.doc = doc + """The function's docstring. + + :type doc: str or None + """ + + self.instance_attrs = {} + super(FunctionDef, self).__init__(lineno, col_offset, parent) + if parent: + frame = parent.frame() + frame.set_local(name, self) + + # pylint: disable=arguments-differ; different than Lambdas + def postinit( + self, + args, + body, + decorators=None, + returns=None, + type_comment_returns=None, + type_comment_args=None, + ): + """Do some setup after initialisation. + + :param args: The arguments that the function takes. + :type args: Arguments or list + + :param body: The contents of the function body. + :type body: list(NodeNG) + + :param decorators: The decorators that are applied to this + method or function. + :type decorators: Decorators or None + :params type_comment_returns: + The return type annotation passed via a type comment. + :params type_comment_args: + The args type annotation passed via a type comment. + """ + self.args = args + self.body = body + self.decorators = decorators + self.returns = returns + self.type_comment_returns = type_comment_returns + self.type_comment_args = type_comment_args + + @decorators_mod.cachedproperty + def extra_decorators(self): + """The extra decorators that this function can have. + + Additional decorators are considered when they are used as + assignments, as in ``method = staticmethod(method)``. + The property will return all the callables that are used for + decoration. + + :type: list(NodeNG) + """ + frame = self.parent.frame() + if not isinstance(frame, ClassDef): + return [] + + decorators = [] + for assign in frame._get_assign_nodes(): + if isinstance(assign.value, node_classes.Call) and isinstance( + assign.value.func, node_classes.Name + ): + for assign_node in assign.targets: + if not isinstance(assign_node, node_classes.AssignName): + # Support only `name = callable(name)` + continue + + if assign_node.name != self.name: + # Interested only in the assignment nodes that + # decorates the current method. + continue + try: + meth = frame[self.name] + except KeyError: + continue + else: + # Must be a function and in the same frame as the + # original method. + if ( + isinstance(meth, FunctionDef) + and assign_node.frame() == frame + ): + decorators.append(assign.value) + return decorators + + @decorators_mod.cachedproperty + def type(self): # pylint: disable=invalid-overridden-method + """The function type for this node. + + Possible values are: method, function, staticmethod, classmethod. + + :type: str + """ + builtin_descriptors = {"classmethod", "staticmethod"} + + for decorator in self.extra_decorators: + if decorator.func.name in builtin_descriptors: + return decorator.func.name + + frame = self.parent.frame() + type_name = "function" + if isinstance(frame, ClassDef): + if self.name == "__new__": + return "classmethod" + if sys.version_info >= (3, 6) and self.name == "__init_subclass__": + return "classmethod" + + type_name = "method" + + if not self.decorators: + return type_name + + for node in self.decorators.nodes: + if isinstance(node, node_classes.Name): + if node.name in builtin_descriptors: + return node.name + + if isinstance(node, node_classes.Call): + # Handle the following case: + # @some_decorator(arg1, arg2) + # def func(...) + # + try: + current = next(node.func.infer()) + except exceptions.InferenceError: + continue + _type = _infer_decorator_callchain(current) + if _type is not None: + return _type + + try: + for inferred in node.infer(): + # Check to see if this returns a static or a class method. + _type = _infer_decorator_callchain(inferred) + if _type is not None: + return _type + + if not isinstance(inferred, ClassDef): + continue + for ancestor in inferred.ancestors(): + if not isinstance(ancestor, ClassDef): + continue + if ancestor.is_subtype_of("%s.classmethod" % BUILTINS): + return "classmethod" + if ancestor.is_subtype_of("%s.staticmethod" % BUILTINS): + return "staticmethod" + except exceptions.InferenceError: + pass + return type_name + + @decorators_mod.cachedproperty + def fromlineno(self): + """The first line that this node appears on in the source code. + + :type: int or None + """ + # lineno is the line number of the first decorator, we want the def + # statement lineno + lineno = self.lineno + if self.decorators is not None: + lineno += sum( + node.tolineno - node.lineno + 1 for node in self.decorators.nodes + ) + + return lineno + + @decorators_mod.cachedproperty + def blockstart_tolineno(self): + """The line on which the beginning of this block ends. + + :type: int + """ + return self.args.tolineno + + def block_range(self, lineno): + """Get a range from the given line number to where this node ends. + + :param lineno: Unused. + :type lineno: int + + :returns: The range of line numbers that this node belongs to, + :rtype: tuple(int, int) + """ + return self.fromlineno, self.tolineno + + def getattr(self, name, context=None): + """this method doesn't look in the instance_attrs dictionary since it's + done by an Instance proxy at inference time. + """ + if name in self.instance_attrs: + return self.instance_attrs[name] + if name in self.special_attributes: + return [self.special_attributes.lookup(name)] + raise exceptions.AttributeInferenceError(target=self, attribute=name) + + def igetattr(self, name, context=None): + """Inferred getattr, which returns an iterator of inferred statements.""" + try: + return bases._infer_stmts(self.getattr(name, context), context, frame=self) + except exceptions.AttributeInferenceError as error: + raise exceptions.InferenceError( + error.message, target=self, attribute=name, context=context + ) from error + + def is_method(self): + """Check if this function node represents a method. + + :returns: True if this is a method, False otherwise. + :rtype: bool + """ + # check we are defined in a ClassDef, because this is usually expected + # (e.g. pylint...) when is_method() return True + return self.type != "function" and isinstance(self.parent.frame(), ClassDef) + + @decorators_mod.cached + def decoratornames(self): + """Get the qualified names of each of the decorators on this function. + + :returns: The names of the decorators. + :rtype: set(str) + """ + result = set() + decoratornodes = [] + if self.decorators is not None: + decoratornodes += self.decorators.nodes + decoratornodes += self.extra_decorators + for decnode in decoratornodes: + try: + for infnode in decnode.infer(): + result.add(infnode.qname()) + except exceptions.InferenceError: + continue + return result + + def is_bound(self): + """Check if the function is bound to an instance or class. + + :returns: True if the function is bound to an instance or class, + False otherwise. + :rtype: bool + """ + return self.type == "classmethod" + + def is_abstract(self, pass_is_abstract=True): + """Check if the method is abstract. + + A method is considered abstract if any of the following is true: + * The only statement is 'raise NotImplementedError' + * The only statement is 'pass' and pass_is_abstract is True + * The method is annotated with abc.astractproperty/abc.abstractmethod + + :returns: True if the method is abstract, False otherwise. + :rtype: bool + """ + if self.decorators: + for node in self.decorators.nodes: + try: + inferred = next(node.infer()) + except exceptions.InferenceError: + continue + if inferred and inferred.qname() in ( + "abc.abstractproperty", + "abc.abstractmethod", + ): + return True + + for child_node in self.body: + if isinstance(child_node, node_classes.Raise): + if child_node.raises_not_implemented(): + return True + return pass_is_abstract and isinstance(child_node, node_classes.Pass) + # empty function is the same as function with a single "pass" statement + if pass_is_abstract: + return True + + def is_generator(self): + """Check if this is a generator function. + + :returns: True is this is a generator function, False otherwise. + :rtype: bool + """ + return next(self._get_yield_nodes_skip_lambdas(), False) + + def infer_call_result(self, caller=None, context=None): + """Infer what the function returns when called. + + :returns: What the function returns. + :rtype: iterable(NodeNG or Uninferable) or None + """ + if self.is_generator(): + if isinstance(self, AsyncFunctionDef): + generator_cls = bases.AsyncGenerator + else: + generator_cls = bases.Generator + result = generator_cls(self) + yield result + return + # This is really a gigantic hack to work around metaclass generators + # that return transient class-generating functions. Pylint's AST structure + # cannot handle a base class object that is only used for calling __new__, + # but does not contribute to the inheritance structure itself. We inject + # a fake class into the hierarchy here for several well-known metaclass + # generators, and filter it out later. + if ( + self.name == "with_metaclass" + and len(self.args.args) == 1 + and self.args.vararg is not None + ): + metaclass = next(caller.args[0].infer(context)) + if isinstance(metaclass, ClassDef): + class_bases = [next(arg.infer(context)) for arg in caller.args[1:]] + new_class = ClassDef(name="temporary_class") + new_class.hide = True + new_class.parent = self + new_class.postinit( + bases=[base for base in class_bases if base != util.Uninferable], + body=[], + decorators=[], + metaclass=metaclass, + ) + yield new_class + return + returns = self._get_return_nodes_skip_functions() + + first_return = next(returns, None) + if not first_return: + if self.body and isinstance(self.body[-1], node_classes.Assert): + yield node_classes.Const(None) + return + + raise exceptions.InferenceError( + "The function does not have any return statements" + ) + + for returnnode in itertools.chain((first_return,), returns): + if returnnode.value is None: + yield node_classes.Const(None) + else: + try: + yield from returnnode.value.infer(context) + except exceptions.InferenceError: + yield util.Uninferable + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`FunctionDef` this is always ``True``. + :rtype: bool + """ + return True + + def get_children(self): + if self.decorators is not None: + yield self.decorators + + yield self.args + + if self.returns is not None: + yield self.returns + + yield from self.body + + def scope_lookup(self, node, name, offset=0): + """Lookup where the given name is assigned.""" + if name == "__class__": + # __class__ is an implicit closure reference created by the compiler + # if any methods in a class body refer to either __class__ or super. + # In our case, we want to be able to look it up in the current scope + # when `__class__` is being used. + frame = self.parent.frame() + if isinstance(frame, ClassDef): + return self, [frame] + return super().scope_lookup(node, name, offset) + + +class AsyncFunctionDef(FunctionDef): + """Class representing an :class:`ast.FunctionDef` node. + + A :class:`AsyncFunctionDef` is an asynchronous function + created with the `async` keyword. + + >>> node = astroid.extract_node(''' + async def func(things): + async for thing in things: + print(thing) + ''') + >>> node + <AsyncFunctionDef.func l.2 at 0x7f23b2e416d8> + >>> node.body[0] + <AsyncFor l.3 at 0x7f23b2e417b8> + """ + + +def _rec_get_names(args, names=None): + """return a list of all argument names""" + if names is None: + names = [] + for arg in args: + if isinstance(arg, node_classes.Tuple): + _rec_get_names(arg.elts, names) + else: + names.append(arg.name) + return names + + +def _is_metaclass(klass, seen=None): + """ Return if the given class can be + used as a metaclass. + """ + if klass.name == "type": + return True + if seen is None: + seen = set() + for base in klass.bases: + try: + for baseobj in base.infer(): + baseobj_name = baseobj.qname() + if baseobj_name in seen: + continue + + seen.add(baseobj_name) + if isinstance(baseobj, bases.Instance): + # not abstract + return False + if baseobj is util.Uninferable: + continue + if baseobj is klass: + continue + if not isinstance(baseobj, ClassDef): + continue + if baseobj._type == "metaclass": + return True + if _is_metaclass(baseobj, seen): + return True + except exceptions.InferenceError: + continue + return False + + +def _class_type(klass, ancestors=None): + """return a ClassDef node type to differ metaclass and exception + from 'regular' classes + """ + # XXX we have to store ancestors in case we have an ancestor loop + if klass._type is not None: + return klass._type + if _is_metaclass(klass): + klass._type = "metaclass" + elif klass.name.endswith("Exception"): + klass._type = "exception" + else: + if ancestors is None: + ancestors = set() + klass_name = klass.qname() + if klass_name in ancestors: + # XXX we are in loop ancestors, and have found no type + klass._type = "class" + return "class" + ancestors.add(klass_name) + for base in klass.ancestors(recurs=False): + name = _class_type(base, ancestors) + if name != "class": + if name == "metaclass" and not _is_metaclass(klass): + # don't propagate it if the current class + # can't be a metaclass + continue + klass._type = base.type + break + if klass._type is None: + klass._type = "class" + return klass._type + + +def get_wrapping_class(node): + """Get the class that wraps the given node. + + We consider that a class wraps a node if the class + is a parent for the said node. + + :returns: The class that wraps the given node + :rtype: ClassDef or None + """ + + klass = node.frame() + while klass is not None and not isinstance(klass, ClassDef): + if klass.parent is None: + klass = None + else: + klass = klass.parent.frame() + return klass + + +class ClassDef(mixins.FilterStmtsMixin, LocalsDictNodeNG, node_classes.Statement): + """Class representing an :class:`ast.ClassDef` node. + + >>> node = astroid.extract_node(''' + class Thing: + def my_meth(self, arg): + return arg + self.offset + ''') + >>> node + <ClassDef.Thing l.2 at 0x7f23b2e9e748> + """ + + # some of the attributes below are set by the builder module or + # by a raw factories + + # a dictionary of class instances attributes + _astroid_fields = ("decorators", "bases", "body") # name + + decorators = None + """The decorators that are applied to this class. + + :type: Decorators or None + """ + special_attributes = objectmodel.ClassModel() + """The names of special attributes that this class has. + + :type: objectmodel.ClassModel + """ + + _type = None + _metaclass_hack = False + hide = False + type = property( + _class_type, + doc=( + "The class type for this node.\n\n" + "Possible values are: class, metaclass, exception.\n\n" + ":type: str" + ), + ) + _other_fields = ("name", "doc") + _other_other_fields = ("locals", "_newstyle") + _newstyle = None + + def __init__(self, name=None, doc=None, lineno=None, col_offset=None, parent=None): + """ + :param name: The name of the class. + :type name: str or None + + :param doc: The function's docstring. + :type doc: str or None + + :param lineno: The line that this node appears on in the source code. + :type lineno: int or None + + :param col_offset: The column that this node appears on in the + source code. + :type col_offset: int or None + + :param parent: The parent node in the syntax tree. + :type parent: NodeNG or None + """ + self.instance_attrs = {} + self.locals = {} + """A map of the name of a local variable to the node defining it. + + :type: dict(str, NodeNG) + """ + + self.keywords = [] + """The keywords given to the class definition. + + This is usually for :pep:`3115` style metaclass declaration. + + :type: list(Keyword) or None + """ + + self.bases = [] + """What the class inherits from. + + :type: list(NodeNG) + """ + + self.body = [] + """The contents of the class body. + + :type: list(NodeNG) + """ + + self.name = name + """The name of the class. + + :type name: str or None + """ + + self.doc = doc + """The class' docstring. + + :type doc: str or None + """ + + super(ClassDef, self).__init__(lineno, col_offset, parent) + if parent is not None: + parent.frame().set_local(name, self) + + for local_name, node in self.implicit_locals(): + self.add_local_node(node, local_name) + + def implicit_parameters(self): + return 1 + + def implicit_locals(self): + """Get implicitly defined class definition locals. + + :returns: the the name and Const pair for each local + :rtype: tuple(tuple(str, node_classes.Const), ...) + """ + locals_ = (("__module__", self.special_attributes.attr___module__),) + # __qualname__ is defined in PEP3155 + locals_ += (("__qualname__", self.special_attributes.attr___qualname__),) + return locals_ + + # pylint: disable=redefined-outer-name + def postinit( + self, bases, body, decorators, newstyle=None, metaclass=None, keywords=None + ): + """Do some setup after initialisation. + + :param bases: What the class inherits from. + :type bases: list(NodeNG) + + :param body: The contents of the class body. + :type body: list(NodeNG) + + :param decorators: The decorators that are applied to this class. + :type decorators: Decorators or None + + :param newstyle: Whether this is a new style class or not. + :type newstyle: bool or None + + :param metaclass: The metaclass of this class. + :type metaclass: NodeNG or None + + :param keywords: The keywords given to the class definition. + :type keywords: list(Keyword) or None + """ + self.keywords = keywords + self.bases = bases + self.body = body + self.decorators = decorators + if newstyle is not None: + self._newstyle = newstyle + if metaclass is not None: + self._metaclass = metaclass + + def _newstyle_impl(self, context=None): + if context is None: + context = contextmod.InferenceContext() + if self._newstyle is not None: + return self._newstyle + for base in self.ancestors(recurs=False, context=context): + if base._newstyle_impl(context): + self._newstyle = True + break + klass = self.declared_metaclass() + # could be any callable, we'd need to infer the result of klass(name, + # bases, dict). punt if it's not a class node. + if klass is not None and isinstance(klass, ClassDef): + self._newstyle = klass._newstyle_impl(context) + if self._newstyle is None: + self._newstyle = False + return self._newstyle + + _newstyle = None + newstyle = property( + _newstyle_impl, + doc=("Whether this is a new style class or not\n\n" ":type: bool or None"), + ) + + @decorators_mod.cachedproperty + def blockstart_tolineno(self): + """The line on which the beginning of this block ends. + + :type: int + """ + if self.bases: + return self.bases[-1].tolineno + + return self.fromlineno + + def block_range(self, lineno): + """Get a range from the given line number to where this node ends. + + :param lineno: Unused. + :type lineno: int + + :returns: The range of line numbers that this node belongs to, + :rtype: tuple(int, int) + """ + return self.fromlineno, self.tolineno + + def pytype(self): + """Get the name of the type that this node represents. + + :returns: The name of the type. + :rtype: str + """ + if self.newstyle: + return "%s.type" % BUILTINS + return "%s.classobj" % BUILTINS + + def display_type(self): + """A human readable type of this node. + + :returns: The type of this node. + :rtype: str + """ + return "Class" + + def callable(self): + """Whether this node defines something that is callable. + + :returns: True if this defines something that is callable, + False otherwise. + For a :class:`ClassDef` this is always ``True``. + :rtype: bool + """ + return True + + def is_subtype_of(self, type_name, context=None): + """Whether this class is a subtype of the given type. + + :param type_name: The name of the type of check against. + :type type_name: str + + :returns: True if this class is a subtype of the given type, + False otherwise. + :rtype: bool + """ + if self.qname() == type_name: + return True + for anc in self.ancestors(context=context): + if anc.qname() == type_name: + return True + return False + + def _infer_type_call(self, caller, context): + name_node = next(caller.args[0].infer(context)) + if isinstance(name_node, node_classes.Const) and isinstance( + name_node.value, str + ): + name = name_node.value + else: + return util.Uninferable + + result = ClassDef(name, None) + + # Get the bases of the class. + class_bases = next(caller.args[1].infer(context)) + if isinstance(class_bases, (node_classes.Tuple, node_classes.List)): + result.bases = class_bases.itered() + else: + # There is currently no AST node that can represent an 'unknown' + # node (Uninferable is not an AST node), therefore we simply return Uninferable here + # although we know at least the name of the class. + return util.Uninferable + + # Get the members of the class + try: + members = next(caller.args[2].infer(context)) + except exceptions.InferenceError: + members = None + + if members and isinstance(members, node_classes.Dict): + for attr, value in members.items: + if isinstance(attr, node_classes.Const) and isinstance(attr.value, str): + result.locals[attr.value] = [value] + + result.parent = caller.parent + return result + + def infer_call_result(self, caller, context=None): + """infer what a class is returning when called""" + if ( + self.is_subtype_of("%s.type" % (BUILTINS,), context) + and len(caller.args) == 3 + ): + result = self._infer_type_call(caller, context) + yield result + return + + dunder_call = None + try: + metaclass = self.metaclass(context=context) + if metaclass is not None: + dunder_call = next(metaclass.igetattr("__call__", context)) + except exceptions.AttributeInferenceError: + pass + + if dunder_call and dunder_call.qname() != "builtins.type.__call__": + # Call type.__call__ if not set metaclass + # (since type is the default metaclass) + context = contextmod.bind_context_to_node(context, self) + yield from dunder_call.infer_call_result(caller, context) + else: + if any(cls.name in EXCEPTION_BASE_CLASSES for cls in self.mro()): + # Subclasses of exceptions can be exception instances + yield objects.ExceptionInstance(self) + else: + yield bases.Instance(self) + + def scope_lookup(self, node, name, offset=0): + """Lookup where the given name is assigned. + + :param node: The node to look for assignments up to. + Any assignments after the given node are ignored. + :type node: NodeNG + + :param name: The name to find assignments for. + :type name: str + + :param offset: The line offset to filter statements up to. + :type offset: int + + :returns: This scope node and the list of assignments associated to the + given name according to the scope where it has been found (locals, + globals or builtin). + :rtype: tuple(str, list(NodeNG)) + """ + # If the name looks like a builtin name, just try to look + # into the upper scope of this class. We might have a + # decorator that it's poorly named after a builtin object + # inside this class. + lookup_upper_frame = ( + isinstance(node.parent, node_classes.Decorators) + and name in MANAGER.builtins_module + ) + if ( + any(node == base or base.parent_of(node) for base in self.bases) + or lookup_upper_frame + ): + # Handle the case where we have either a name + # in the bases of a class, which exists before + # the actual definition or the case where we have + # a Getattr node, with that name. + # + # name = ... + # class A(name): + # def name(self): ... + # + # import name + # class A(name.Name): + # def name(self): ... + + frame = self.parent.frame() + # line offset to avoid that class A(A) resolve the ancestor to + # the defined class + offset = -1 + else: + frame = self + return frame._scope_lookup(node, name, offset) + + @property + def basenames(self): + """The names of the parent classes + + Names are given in the order they appear in the class definition. + + :type: list(str) + """ + return [bnode.as_string() for bnode in self.bases] + + def ancestors(self, recurs=True, context=None): + """Iterate over the base classes in prefixed depth first order. + + :param recurs: Whether to recurse or return direct ancestors only. + :type recurs: bool + + :returns: The base classes + :rtype: iterable(NodeNG) + """ + # FIXME: should be possible to choose the resolution order + # FIXME: inference make infinite loops possible here + yielded = {self} + if context is None: + context = contextmod.InferenceContext() + if not self.bases and self.qname() != "builtins.object": + yield builtin_lookup("object")[1][0] + return + + for stmt in self.bases: + with context.restore_path(): + try: + for baseobj in stmt.infer(context): + if not isinstance(baseobj, ClassDef): + if isinstance(baseobj, bases.Instance): + baseobj = baseobj._proxied + else: + continue + if not baseobj.hide: + if baseobj in yielded: + continue + yielded.add(baseobj) + yield baseobj + if not recurs: + continue + for grandpa in baseobj.ancestors(recurs=True, context=context): + if grandpa is self: + # This class is the ancestor of itself. + break + if grandpa in yielded: + continue + yielded.add(grandpa) + yield grandpa + except exceptions.InferenceError: + continue + + def local_attr_ancestors(self, name, context=None): + """Iterate over the parents that define the given name. + + :param name: The name to find definitions for. + :type name: str + + :returns: The parents that define the given name. + :rtype: iterable(NodeNG) + """ + # Look up in the mro if we can. This will result in the + # attribute being looked up just as Python does it. + try: + ancestors = self.mro(context)[1:] + except exceptions.MroError: + # Fallback to use ancestors, we can't determine + # a sane MRO. + ancestors = self.ancestors(context=context) + for astroid in ancestors: + if name in astroid: + yield astroid + + def instance_attr_ancestors(self, name, context=None): + """Iterate over the parents that define the given name as an attribute. + + :param name: The name to find definitions for. + :type name: str + + :returns: The parents that define the given name as + an instance attribute. + :rtype: iterable(NodeNG) + """ + for astroid in self.ancestors(context=context): + if name in astroid.instance_attrs: + yield astroid + + def has_base(self, node): + """Whether this class directly inherits from the given node. + + :param node: The node to check for. + :type node: NodeNG + + :returns: True if this class directly inherits from the given node. + :rtype: bool + """ + return node in self.bases + + def local_attr(self, name, context=None): + """Get the list of assign nodes associated to the given name. + + Assignments are looked for in both this class and in parents. + + :returns: The list of assignments to the given name. + :rtype: list(NodeNG) + + :raises AttributeInferenceError: If no attribute with this name + can be found in this class or parent classes. + """ + result = [] + if name in self.locals: + result = self.locals[name] + else: + class_node = next(self.local_attr_ancestors(name, context), None) + if class_node: + result = class_node.locals[name] + result = [n for n in result if not isinstance(n, node_classes.DelAttr)] + if result: + return result + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) + + def instance_attr(self, name, context=None): + """Get the list of nodes associated to the given attribute name. + + Assignments are looked for in both this class and in parents. + + :returns: The list of assignments to the given name. + :rtype: list(NodeNG) + + :raises AttributeInferenceError: If no attribute with this name + can be found in this class or parent classes. + """ + # Return a copy, so we don't modify self.instance_attrs, + # which could lead to infinite loop. + values = list(self.instance_attrs.get(name, [])) + # get all values from parents + for class_node in self.instance_attr_ancestors(name, context): + values += class_node.instance_attrs[name] + values = [n for n in values if not isinstance(n, node_classes.DelAttr)] + if values: + return values + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) + + def instantiate_class(self): + """Get an :class:`Instance` of the :class:`ClassDef` node. + + :returns: An :class:`Instance` of the :class:`ClassDef` node, + or self if this is not possible. + :rtype: Instance or ClassDef + """ + return bases.Instance(self) + + def getattr(self, name, context=None, class_context=True): + """Get an attribute from this class, using Python's attribute semantic. + + This method doesn't look in the :attr:`instance_attrs` dictionary + since it is done by an :class:`Instance` proxy at inference time. + It may return an :class:`Uninferable` object if + the attribute has not been + found, but a ``__getattr__`` or ``__getattribute__`` method is defined. + If ``class_context`` is given, then it is considered that the + attribute is accessed from a class context, + e.g. ClassDef.attribute, otherwise it might have been accessed + from an instance as well. If ``class_context`` is used in that + case, then a lookup in the implicit metaclass and the explicit + metaclass will be done. + + :param name: The attribute to look for. + :type name: str + + :param class_context: Whether the attribute can be accessed statically. + :type class_context: bool + + :returns: The attribute. + :rtype: list(NodeNG) + + :raises AttributeInferenceError: If the attribute cannot be inferred. + """ + values = self.locals.get(name, []) + if name in self.special_attributes and class_context and not values: + result = [self.special_attributes.lookup(name)] + if name == "__bases__": + # Need special treatment, since they are mutable + # and we need to return all the values. + result += values + return result + + # don't modify the list in self.locals! + values = list(values) + for classnode in self.ancestors(recurs=True, context=context): + values += classnode.locals.get(name, []) + + if class_context: + values += self._metaclass_lookup_attribute(name, context) + + if not values: + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) + + # Look for AnnAssigns, which are not attributes in the purest sense. + for value in values: + if isinstance(value, node_classes.AssignName): + stmt = value.statement() + if isinstance(stmt, node_classes.AnnAssign) and stmt.value is None: + raise exceptions.AttributeInferenceError( + target=self, attribute=name, context=context + ) + return values + + def _metaclass_lookup_attribute(self, name, context): + """Search the given name in the implicit and the explicit metaclass.""" + attrs = set() + implicit_meta = self.implicit_metaclass() + metaclass = self.metaclass() + for cls in {implicit_meta, metaclass}: + if cls and cls != self and isinstance(cls, ClassDef): + cls_attributes = self._get_attribute_from_metaclass(cls, name, context) + attrs.update(set(cls_attributes)) + return attrs + + def _get_attribute_from_metaclass(self, cls, name, context): + try: + attrs = cls.getattr(name, context=context, class_context=True) + except exceptions.AttributeInferenceError: + return + + for attr in bases._infer_stmts(attrs, context, frame=cls): + if not isinstance(attr, FunctionDef): + yield attr + continue + + if bases._is_property(attr): + yield from attr.infer_call_result(self, context) + continue + if attr.type == "classmethod": + # If the method is a classmethod, then it will + # be bound to the metaclass, not to the class + # from where the attribute is retrieved. + # get_wrapping_class could return None, so just + # default to the current class. + frame = get_wrapping_class(attr) or self + yield bases.BoundMethod(attr, frame) + elif attr.type == "staticmethod": + yield attr + else: + yield bases.BoundMethod(attr, self) + + def igetattr(self, name, context=None, class_context=True): + """Infer the possible values of the given variable. + + :param name: The name of the variable to infer. + :type name: str + + :returns: The inferred possible values. + :rtype: iterable(NodeNG or Uninferable) + """ + # set lookup name since this is necessary to infer on import nodes for + # instance + context = contextmod.copy_context(context) + context.lookupname = name + try: + attr = self.getattr(name, context, class_context=class_context)[0] + for inferred in bases._infer_stmts([attr], context, frame=self): + # yield Uninferable object instead of descriptors when necessary + if not isinstance(inferred, node_classes.Const) and isinstance( + inferred, bases.Instance + ): + try: + inferred._proxied.getattr("__get__", context) + except exceptions.AttributeInferenceError: + yield inferred + else: + yield util.Uninferable + else: + yield function_to_method(inferred, self) + except exceptions.AttributeInferenceError as error: + if not name.startswith("__") and self.has_dynamic_getattr(context): + # class handle some dynamic attributes, return a Uninferable object + yield util.Uninferable + else: + raise exceptions.InferenceError( + error.message, target=self, attribute=name, context=context + ) + + def has_dynamic_getattr(self, context=None): + """Check if the class has a custom __getattr__ or __getattribute__. + + If any such method is found and it is not from + builtins, nor from an extension module, then the function + will return True. + + :returns: True if the class has a custom + __getattr__ or __getattribute__, False otherwise. + :rtype: bool + """ + + def _valid_getattr(node): + root = node.root() + return root.name != BUILTINS and getattr(root, "pure_python", None) + + try: + return _valid_getattr(self.getattr("__getattr__", context)[0]) + except exceptions.AttributeInferenceError: + # if self.newstyle: XXX cause an infinite recursion error + try: + getattribute = self.getattr("__getattribute__", context)[0] + return _valid_getattr(getattribute) + except exceptions.AttributeInferenceError: + pass + return False + + def getitem(self, index, context=None): + """Return the inference of a subscript. + + This is basically looking up the method in the metaclass and calling it. + + :returns: The inferred value of a subscript to this class. + :rtype: NodeNG + + :raises AstroidTypeError: If this class does not define a + ``__getitem__`` method. + """ + try: + methods = dunder_lookup.lookup(self, "__getitem__") + except exceptions.AttributeInferenceError as exc: + raise exceptions.AstroidTypeError(node=self, context=context) from exc + + method = methods[0] + + # Create a new callcontext for providing index as an argument. + new_context = contextmod.bind_context_to_node(context, self) + new_context.callcontext = contextmod.CallContext(args=[index]) + + try: + return next(method.infer_call_result(self, new_context)) + except exceptions.InferenceError: + return util.Uninferable + + def methods(self): + """Iterate over all of the method defined in this class and its parents. + + :returns: The methods defined on the class. + :rtype: iterable(FunctionDef) + """ + done = {} + for astroid in itertools.chain(iter((self,)), self.ancestors()): + for meth in astroid.mymethods(): + if meth.name in done: + continue + done[meth.name] = None + yield meth + + def mymethods(self): + """Iterate over all of the method defined in this class only. + + :returns: The methods defined on the class. + :rtype: iterable(FunctionDef) + """ + for member in self.values(): + if isinstance(member, FunctionDef): + yield member + + def implicit_metaclass(self): + """Get the implicit metaclass of the current class. + + For newstyle classes, this will return an instance of builtins.type. + For oldstyle classes, it will simply return None, since there's + no implicit metaclass there. + + :returns: The metaclass. + :rtype: builtins.type or None + """ + if self.newstyle: + return builtin_lookup("type")[1][0] + return None + + _metaclass = None + + def declared_metaclass(self, context=None): + """Return the explicit declared metaclass for the current class. + + An explicit declared metaclass is defined + either by passing the ``metaclass`` keyword argument + in the class definition line (Python 3) or (Python 2) by + having a ``__metaclass__`` class attribute, or if there are + no explicit bases but there is a global ``__metaclass__`` variable. + + :returns: The metaclass of this class, + or None if one could not be found. + :rtype: NodeNG or None + """ + for base in self.bases: + try: + for baseobj in base.infer(context=context): + if isinstance(baseobj, ClassDef) and baseobj.hide: + self._metaclass = baseobj._metaclass + self._metaclass_hack = True + break + except exceptions.InferenceError: + pass + + if self._metaclass: + # Expects this from Py3k TreeRebuilder + try: + return next( + node + for node in self._metaclass.infer(context=context) + if node is not util.Uninferable + ) + except (exceptions.InferenceError, StopIteration): + return None + + return None + + def _find_metaclass(self, seen=None, context=None): + if seen is None: + seen = set() + seen.add(self) + + klass = self.declared_metaclass(context=context) + if klass is None: + for parent in self.ancestors(context=context): + if parent not in seen: + klass = parent._find_metaclass(seen) + if klass is not None: + break + return klass + + def metaclass(self, context=None): + """Get the metaclass of this class. + + If this class does not define explicitly a metaclass, + then the first defined metaclass in ancestors will be used + instead. + + :returns: The metaclass of this class. + :rtype: NodeNG or None + """ + return self._find_metaclass(context=context) + + def has_metaclass_hack(self): + return self._metaclass_hack + + def _islots(self): + """ Return an iterator with the inferred slots. """ + if "__slots__" not in self.locals: + return None + for slots in self.igetattr("__slots__"): + # check if __slots__ is a valid type + for meth in ITER_METHODS: + try: + slots.getattr(meth) + break + except exceptions.AttributeInferenceError: + continue + else: + continue + + if isinstance(slots, node_classes.Const): + # a string. Ignore the following checks, + # but yield the node, only if it has a value + if slots.value: + yield slots + continue + if not hasattr(slots, "itered"): + # we can't obtain the values, maybe a .deque? + continue + + if isinstance(slots, node_classes.Dict): + values = [item[0] for item in slots.items] + else: + values = slots.itered() + if values is util.Uninferable: + continue + if not values: + # Stop the iteration, because the class + # has an empty list of slots. + return values + + for elt in values: + try: + for inferred in elt.infer(): + if inferred is util.Uninferable: + continue + if not isinstance( + inferred, node_classes.Const + ) or not isinstance(inferred.value, str): + continue + if not inferred.value: + continue + yield inferred + except exceptions.InferenceError: + continue + + return None + + def _slots(self): + if not self.newstyle: + raise NotImplementedError( + "The concept of slots is undefined for old-style classes." + ) + + slots = self._islots() + try: + first = next(slots) + except StopIteration as exc: + # The class doesn't have a __slots__ definition or empty slots. + if exc.args and exc.args[0] not in ("", None): + return exc.args[0] + return None + return [first] + list(slots) + + # Cached, because inferring them all the time is expensive + @decorators_mod.cached + def slots(self): + """Get all the slots for this node. + + :returns: The names of slots for this class. + If the class doesn't define any slot, through the ``__slots__`` + variable, then this function will return a None. + Also, it will return None in the case the slots were not inferred. + :rtype: list(str) or None + """ + + def grouped_slots(): + # Not interested in object, since it can't have slots. + for cls in self.mro()[:-1]: + try: + cls_slots = cls._slots() + except NotImplementedError: + continue + if cls_slots is not None: + yield from cls_slots + else: + yield None + + if not self.newstyle: + raise NotImplementedError( + "The concept of slots is undefined for old-style classes." + ) + + slots = list(grouped_slots()) + if not all(slot is not None for slot in slots): + return None + + return sorted(slots, key=lambda item: item.value) + + def _inferred_bases(self, context=None): + # Similar with .ancestors, but the difference is when one base is inferred, + # only the first object is wanted. That's because + # we aren't interested in superclasses, as in the following + # example: + # + # class SomeSuperClass(object): pass + # class SomeClass(SomeSuperClass): pass + # class Test(SomeClass): pass + # + # Inferring SomeClass from the Test's bases will give + # us both SomeClass and SomeSuperClass, but we are interested + # only in SomeClass. + + if context is None: + context = contextmod.InferenceContext() + if not self.bases and self.qname() != "builtins.object": + yield builtin_lookup("object")[1][0] + return + + for stmt in self.bases: + try: + baseobj = next(stmt.infer(context=context)) + except exceptions.InferenceError: + continue + if isinstance(baseobj, bases.Instance): + baseobj = baseobj._proxied + if not isinstance(baseobj, ClassDef): + continue + if not baseobj.hide: + yield baseobj + else: + yield from baseobj.bases + + def _compute_mro(self, context=None): + inferred_bases = list(self._inferred_bases(context=context)) + bases_mro = [] + for base in inferred_bases: + if base is self: + continue + + try: + mro = base._compute_mro(context=context) + bases_mro.append(mro) + except NotImplementedError: + # Some classes have in their ancestors both newstyle and + # old style classes. For these we can't retrieve the .mro, + # although in Python it's possible, since the class we are + # currently working is in fact new style. + # So, we fallback to ancestors here. + ancestors = list(base.ancestors(context=context)) + bases_mro.append(ancestors) + + unmerged_mro = [[self]] + bases_mro + [inferred_bases] + unmerged_mro = list(clean_duplicates_mro(unmerged_mro, self, context)) + return _c3_merge(unmerged_mro, self, context) + + def mro(self, context=None) -> List["ClassDef"]: + """Get the method resolution order, using C3 linearization. + + :returns: The list of ancestors, sorted by the mro. + :rtype: list(NodeNG) + :raises DuplicateBasesError: Duplicate bases in the same class base + :raises InconsistentMroError: A class' MRO is inconsistent + """ + return self._compute_mro(context=context) + + def bool_value(self): + """Determine the boolean value of this node. + + :returns: The boolean value of this node. + For a :class:`ClassDef` this is always ``True``. + :rtype: bool + """ + return True + + def get_children(self): + if self.decorators is not None: + yield self.decorators + + yield from self.bases + yield from self.body + + @decorators_mod.cached + def _get_assign_nodes(self): + children_assign_nodes = ( + child_node._get_assign_nodes() for child_node in self.body + ) + return list(itertools.chain.from_iterable(children_assign_nodes)) |