Fixed being unable to access class attributes on a NamedTuple (#673)

Close pylint-dev/pylint#1628

Author: AWhetter

ChangeLog

@@ -55,6 +55,10 @@ Release Date: TBA
 
   Close #665
 
+* Fix being unable to access class attributes on a NamedTuple.
+
+  Close PyCQA/pylint#1628
+
 
 What's New in astroid 2.2.0?
 ============================

astroid/brain/brain_namedtuple_enum.py

@@ -381,6 +381,15 @@ def infer_typing_namedtuple_class(class_node, context=None):
     generated_class_node = next(infer_named_tuple(node, context))
     for method in class_node.mymethods():
         generated_class_node.locals[method.name] = [method]
+
+    for assign in class_node.body:
+        if not isinstance(assign, nodes.Assign):
+            continue
+
+        for target in assign.targets:
+            attr = target.name
+            generated_class_node.locals[attr] = class_node.locals[attr]
+
     return iter((generated_class_node,))
 
 

astroid/tests/unittest_brain.py

@@ -1006,6 +1006,7 @@ def test_namedtuple_class_form(self):
         from typing import NamedTuple
 
         class Example(NamedTuple):
+            CLASS_ATTR = "class_attr"
             mything: int
 
         Example(mything=1)
@@ -1014,6 +1015,11 @@ class Example(NamedTuple):
         inferred = next(result.infer())
         self.assertIsInstance(inferred, astroid.Instance)
 
+        class_attr = inferred.getattr("CLASS_ATTR")[0]
+        self.assertIsInstance(class_attr, astroid.AssignName)
+        const = next(class_attr.infer())
+        self.assertEqual(const.value, "class_attr")
+
     def test_typing_types(self):
         ast_nodes = builder.extract_node(
             """