diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index 9a3e64289ee877..a3fad6f35e7136 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -3546,6 +3546,22 @@ def close(self): self.assertIsSubclass(B, Custom) self.assertNotIsSubclass(A, Custom) + @runtime_checkable + class ReleasableBuffer(collections.abc.Buffer, Protocol): + def __release_buffer__(self, mv: memoryview) -> None: ... + + class C: pass + class D: + def __buffer__(self, flags: int) -> memoryview: + return memoryview(b'') + def __release_buffer__(self, mv: memoryview) -> None: + pass + + self.assertIsSubclass(D, ReleasableBuffer) + self.assertIsInstance(D(), ReleasableBuffer) + self.assertNotIsSubclass(C, ReleasableBuffer) + self.assertNotIsInstance(C(), ReleasableBuffer) + def test_builtin_protocol_allowlist(self): with self.assertRaises(TypeError): class CustomProtocol(TestCase, Protocol): diff --git a/Lib/typing.py b/Lib/typing.py index 96393d6a02815b..88837db4b744ab 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -1745,7 +1745,7 @@ def _allow_reckless_class_checks(depth=3): _PROTO_ALLOWLIST = { 'collections.abc': [ 'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable', - 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', + 'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', 'Buffer', ], 'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'], } diff --git a/Misc/NEWS.d/next/Library/2023-05-23-17-43-52.gh-issue-104797.NR7KzF.rst b/Misc/NEWS.d/next/Library/2023-05-23-17-43-52.gh-issue-104797.NR7KzF.rst new file mode 100644 index 00000000000000..60c9a0601cdc9a --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-05-23-17-43-52.gh-issue-104797.NR7KzF.rst @@ -0,0 +1,2 @@ +Allow :class:`typing.Protocol` classes to inherit from +:class:`collections.abc.Buffer`. Patch by Jelle Zijlstra.