1 files changed, 99 insertions, 0 deletions
diff --git a/lib/python2.7/lib2to3/fixes/fix_import.py b/lib/python2.7/lib2to3/fixes/fix_import.py
new file mode 100644
index 0000000..88e9d10
--- /dev/null
+++ b/lib/python2.7/lib2to3/fixes/fix_import.py
@@ -0,0 +1,99 @@
+"""Fixer for import statements.
+If spam is being imported from the local directory, this import:
+    from spam import eggs
+Becomes:
+    from .spam import eggs
+
+And this import:
+    import spam
+Becomes:
+    from . import spam
+"""
+
+# Local imports
+from .. import fixer_base
+from os.path import dirname, join, exists, sep
+from ..fixer_util import FromImport, syms, token
+
+
+def traverse_imports(names):
+    """
+    Walks over all the names imported in a dotted_as_names node.
+    """
+    pending = [names]
+    while pending:
+        node = pending.pop()
+        if node.type == token.NAME:
+            yield node.value
+        elif node.type == syms.dotted_name:
+            yield "".join([ch.value for ch in node.children])
+        elif node.type == syms.dotted_as_name:
+            pending.append(node.children[0])
+        elif node.type == syms.dotted_as_names:
+            pending.extend(node.children[::-2])
+        else:
+            raise AssertionError("unknown node type")
+
+
+class FixImport(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = """
+    import_from< 'from' imp=any 'import' ['('] any [')'] >
+    |
+    import_name< 'import' imp=any >
+    """
+
+    def start_tree(self, tree, name):
+        super(FixImport, self).start_tree(tree, name)
+        self.skip = "absolute_import" in tree.future_features
+
+    def transform(self, node, results):
+        if self.skip:
+            return
+        imp = results['imp']
+
+        if node.type == syms.import_from:
+            # Some imps are top-level (eg: 'import ham')
+            # some are first level (eg: 'import ham.eggs')
+            # some are third level (eg: 'import ham.eggs as spam')
+            # Hence, the loop
+            while not hasattr(imp, 'value'):
+                imp = imp.children[0]
+            if self.probably_a_local_import(imp.value):
+                imp.value = u"." + imp.value
+                imp.changed()
+        else:
+            have_local = False
+            have_absolute = False
+            for mod_name in traverse_imports(imp):
+                if self.probably_a_local_import(mod_name):
+                    have_local = True
+                else:
+                    have_absolute = True
+            if have_absolute:
+                if have_local:
+                    # We won't handle both sibling and absolute imports in the
+                    # same statement at the moment.
+                    self.warning(node, "absolute and local imports together")
+                return
+
+            new = FromImport(u".", [imp])
+            new.prefix = node.prefix
+            return new
+
+    def probably_a_local_import(self, imp_name):
+        if imp_name.startswith(u"."):
+            # Relative imports are certainly not local imports.
+            return False
+        imp_name = imp_name.split(u".", 1)[0]
+        base_path = dirname(self.filename)
+        base_path = join(base_path, imp_name)
+        # If there is no __init__.py next to the file its not in a package
+        # so can't be a relative import.
+        if not exists(join(dirname(base_path), "__init__.py")):
+            return False
+        for ext in [".py", sep, ".pyc", ".so", ".sl", ".pyd"]:
+            if exists(base_path + ext):
+                return True
+        return False