pep 484: explicit reexport as intended (#4586)

See discussion on typing-sig.
This doesn't take care of some third_party libraries, will follow up on
those.

Co-authored-by: hauntsaninja <>

stdlib/3/collections/__init__.pyi

@@ -1,7 +1,7 @@
 import sys
 import typing
 from typing import (
-    AbstractSet as Set,
+    AbstractSet,
     Any,
     AsyncIterable as AsyncIterable,
     AsyncIterator as AsyncIterator,
@@ -36,6 +36,8 @@ from typing import (
     overload,
 )
 
+Set = AbstractSet
+
 if sys.version_info >= (3, 6):
     from typing import AsyncGenerator as AsyncGenerator, Collection as Collection