gh-126699: allow AsyncIterator to be used as a base for Protocols (#126702)

Author: tungol

Lib/test/test_typing.py

@@ -4255,6 +4255,9 @@ class CustomProtocol(TestCase, Protocol):
  class CustomContextManager(typing.ContextManager, Protocol):
  pass
 
+ class CustomAsyncIterator(typing.AsyncIterator, Protocol):
+ pass
+
  def test_non_runtime_protocol_isinstance_check(self):
  class P(Protocol):
  x: int

Lib/typing.py

@@ -1940,7 +1940,8 @@ def _allow_reckless_class_checks(depth=2):
 _PROTO_ALLOWLIST = {
  'collections.abc': [
  'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable',
- 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', 'Buffer',
+ 'AsyncIterator', 'Hashable', 'Sized', 'Container', 'Collection',
+ 'Reversible', 'Buffer',
  ],
  'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'],
 }

Misc/NEWS.d/next/Library/2024-11-11-13-24-22.gh-issue-126699.ONGbMd.rst

@@ -0,0 +1 @@
+Allow :class:`collections.abc.AsyncIterator` to be a base for Protocols.