bpo-35843: Implement __getitem__ for _NamespacePath (GH-11690)

Author: asottile

Lib/importlib/_bootstrap_external.py

@@ -1163,6 +1163,9 @@ def _recalculate(self):
     def __iter__(self):
         return iter(self._recalculate())
 
+    def __getitem__(self, index):
+        return self._recalculate()[index]
+
     def __setitem__(self, index, path):
         self._path[index] = path
 

Lib/test/test_importlib/test_namespace_pkgs.py

@@ -332,6 +332,12 @@ def test_namespace_origin_consistency(self):
         self.assertIsNone(foo.__spec__.origin)
         self.assertIsNone(foo.__file__)
 
+    def test_path_indexable(self):
+        # bpo-35843
+        import foo
+        expected_path = os.path.join(self.root, 'portion1', 'foo')
+        self.assertEqual(foo.__path__[0], expected_path)
+
 
 if __name__ == "__main__":
     unittest.main()

Misc/NEWS.d/next/Library/2019-01-28-10-19-40.bpo-35843.7rXGQE.rst

@@ -0,0 +1 @@
+Implement ``__getitem__`` for ``_NamespacePath``.  Patch by Anthony Sottile.