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
 

stdlib/3/os/__init__.pyi

@@ -8,7 +8,7 @@ from _typeshed import (
     OpenBinaryModeWriting,
     OpenTextMode,
 )
-from builtins import OSError as error
+from builtins import OSError
 from io import BufferedRandom, BufferedReader, BufferedWriter, FileIO, TextIOWrapper as _TextIOWrapper
 from posix import listdir as listdir, times_result
 from typing import (
@@ -46,6 +46,8 @@ _T = TypeVar("_T")
 
 # ----- os variables -----
 
+error = OSError
+
 supports_bytes_environ: bool
 
 supports_dir_fd: Set[Callable[..., Any]]
@@ -268,7 +270,9 @@ class stat_result:
     st_type: int
 
 if sys.version_info >= (3, 6):
-    from builtins import _PathLike as PathLike  # See comment in builtins
+    from builtins import _PathLike
+
+    PathLike = _PathLike  # See comment in builtins
 
 _FdOrAnyPath = Union[int, AnyPath]
 

stdlib/3/platform.pyi

@@ -3,7 +3,9 @@
 import sys
 
 if sys.version_info < (3, 9):
-    from os import devnull as DEV_NULL
+    import os
+
+    DEV_NULL = os.devnull
 from typing import NamedTuple, Optional, Tuple
 
 if sys.version_info >= (3, 8):