Skip to content

gh-105237: Allow calling issubclass(X, typing.Protocol) again #105239

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JelleZijlstra merged 6 commits into from
Jun 5, 2023
Merged

gh-105237: Allow calling issubclass(X, typing.Protocol) again #105239

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
a6b11b0
Allow calling `issubclass(X, Protocol)`
AlexWaygood Jun 2, 2023
36b2ac9
Add back some implementation details so we don't unnecessarily break …
AlexWaygood Jun 2, 2023
db51c8d
Revert unnecessary changes to tests
AlexWaygood Jun 2, 2023
776bf2b
Fix longstanding bug and add many tests
AlexWaygood Jun 2, 2023
ffb7f1c
Small micro-optimisation
AlexWaygood Jun 2, 2023
b85a320
Cleaner solution
AlexWaygood Jun 2, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 12 additions & 2 deletions Lib/test/test_typing.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2758,6 +2758,16 @@ def x(self): ...
with self.assertRaisesRegex(TypeError, only_classes_allowed):
issubclass(1, BadPG)

for proto in P, PG, BadP, BadPG:
with self.subTest(proto=proto.__name__):
self.assertIsSubclass(proto, Protocol)

# TODO: the behaviour of some of these is questionable!
# For now, just check that these don't raise any Exceptions
issubclass(object, Protocol)
issubclass(str, Protocol)
issubclass(C, Protocol)
Comment thread
AlexWaygood marked this conversation as resolved.
Outdated

def test_protocols_issubclass_non_callable(self):
class C:
x = 1
Expand Down Expand Up @@ -3505,8 +3515,8 @@ def meth(self):
self.assertTrue(P._is_protocol)
self.assertTrue(PR._is_protocol)
self.assertTrue(PG._is_protocol)
self.assertFalse(P._is_runtime_protocol)
self.assertTrue(PR._is_runtime_protocol)
self.assertFalse(getattr(P, "_is_runtime_protocol", False))
self.assertTrue(getattr(PR, "_is_runtime_protocol", False))
self.assertTrue(PG[int]._is_protocol)
self.assertEqual(typing._get_protocol_attrs(P), {'meth'})
self.assertEqual(typing._get_protocol_attrs(PR), {'x'})
Expand Down
4 changes: 1 addition & 3 deletions Lib/typing.py
View file
Open in desktop
Comment thread
AlexWaygood marked this conversation as resolved.
Original file line number Diff line number Diff line change
Expand Up @@ -1862,8 +1862,6 @@ def meth(self) -> T:
...
"""
__slots__ = ()
_is_protocol = True
Comment thread
AlexWaygood marked this conversation as resolved.
_is_runtime_protocol = False

def __init_subclass__(cls, *args, **kwargs):
super().__init_subclass__(*args, **kwargs)
Expand Down Expand Up @@ -1904,7 +1902,7 @@ def _proto_hook(other):

# ... otherwise check consistency of bases, and prohibit instantiation.
for base in cls.__bases__:
if not (base in (object, Generic) or
if not (base in {object, Generic, Protocol} or
base.__module__ in _PROTO_ALLOWLIST and
base.__name__ in _PROTO_ALLOWLIST[base.__module__] or
issubclass(base, Generic) and getattr(base, '_is_protocol', False)):
Expand Down