Initial commit

venv/lib/python3.8/site-packages/astroid/interpreter/dunder_lookup.py

@@ -0,0 +1,66 @@
+# Copyright (c) 2016-2018 Claudiu Popa <pcmanticore@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
+
+"""Contains logic for retrieving special methods.
+
+This implementation does not rely on the dot attribute access
+logic, found in ``.getattr()``. The difference between these two
+is that the dunder methods are looked with the type slots
+(you can find more about these here
+http://lucumr.pocoo.org/2014/8/16/the-python-i-would-like-to-see/)
+As such, the lookup for the special methods is actually simpler than
+the dot attribute access.
+"""
+import itertools
+
+import astroid
+from astroid import exceptions
+
+
+def _lookup_in_mro(node, name):
+    attrs = node.locals.get(name, [])
+
+    nodes = itertools.chain.from_iterable(
+        ancestor.locals.get(name, []) for ancestor in node.ancestors(recurs=True)
+    )
+    values = list(itertools.chain(attrs, nodes))
+    if not values:
+        raise exceptions.AttributeInferenceError(attribute=name, target=node)
+
+    return values
+
+
+def lookup(node, name):
+    """Lookup the given special method name in the given *node*
+
+    If the special method was found, then a list of attributes
+    will be returned. Otherwise, `astroid.AttributeInferenceError`
+    is going to be raised.
+    """
+    if isinstance(
+        node, (astroid.List, astroid.Tuple, astroid.Const, astroid.Dict, astroid.Set)
+    ):
+        return _builtin_lookup(node, name)
+    if isinstance(node, astroid.Instance):
+        return _lookup_in_mro(node, name)
+    if isinstance(node, astroid.ClassDef):
+        return _class_lookup(node, name)
+
+    raise exceptions.AttributeInferenceError(attribute=name, target=node)
+
+
+def _class_lookup(node, name):
+    metaclass = node.metaclass()
+    if metaclass is None:
+        raise exceptions.AttributeInferenceError(attribute=name, target=node)
+
+    return _lookup_in_mro(metaclass, name)
+
+
+def _builtin_lookup(node, name):
+    values = node.locals.get(name, [])
+    if not values:
+        raise exceptions.AttributeInferenceError(attribute=name, target=node)
+
+    return values