[Python-checkins] [3.9] bpo-38908: Fix issue when non runtime_protocol does not raise TypeError (GH-26067) (GH-26075)
miss-islington
webhook-mailer at python.org
Wed May 12 13:04:55 EDT 2021
https://github.com/python/cpython/commit/88136bbd0500b688c05e914be031cd3c243e42d8
commit: 88136bbd0500b688c05e914be031cd3c243e42d8
branch: 3.9
author: Ken Jin <28750310+Fidget-Spinner at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2021-05-12T10:04:43-07:00
summary:
[3.9] bpo-38908: Fix issue when non runtime_protocol does not raise TypeError (GH-26067) (GH-26075)
(cherry picked from commit c40486a)
Co-authored-by: Yurii Karabas 1998uriyyo at gmail.com
Automerge-Triggered-By: GH:gvanrossum
files:
A Misc/NEWS.d/next/Library/2021-05-12-16-43-21.bpo-38908.nM2_rO.rst
M Lib/test/test_typing.py
M Lib/typing.py
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 4bdb2a0fad6c7..d91363eb37960 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -1422,6 +1422,14 @@ class CustomProtocol(TestCase, Protocol):
class CustomContextManager(typing.ContextManager, Protocol):
pass
+ def test_non_runtime_protocol_isinstance_check(self):
+ class P(Protocol):
+ x: int
+
+ with self.assertRaisesRegex(TypeError, "@runtime_checkable"):
+ isinstance(1, P)
+
+
class GenericTests(BaseTestCase):
def test_basics(self):
diff --git a/Lib/typing.py b/Lib/typing.py
index 123fbc2c45010..c3844cf3083e1 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1079,14 +1079,14 @@ def _no_init(self, *args, **kwargs):
raise TypeError('Protocols cannot be instantiated')
-def _allow_reckless_class_cheks():
+def _allow_reckless_class_checks(depth=3):
"""Allow instance and class checks for special stdlib modules.
The abc and functools modules indiscriminately call isinstance() and
issubclass() on the whole MRO of a user class, which may contain protocols.
"""
try:
- return sys._getframe(3).f_globals['__name__'] in ['abc', 'functools']
+ return sys._getframe(depth).f_globals['__name__'] in ['abc', 'functools']
except (AttributeError, ValueError): # For platforms without _getframe().
return True
@@ -1106,6 +1106,14 @@ class _ProtocolMeta(ABCMeta):
def __instancecheck__(cls, instance):
# We need this method for situations where attributes are
# assigned in __init__.
+ if (
+ getattr(cls, '_is_protocol', False) and
+ not getattr(cls, '_is_runtime_protocol', False) and
+ not _allow_reckless_class_checks(depth=2)
+ ):
+ raise TypeError("Instance and class checks can only be used with"
+ " @runtime_checkable protocols")
+
if ((not getattr(cls, '_is_protocol', False) or
_is_callable_members_only(cls)) and
issubclass(instance.__class__, cls)):
@@ -1168,12 +1176,12 @@ def _proto_hook(other):
# First, perform various sanity checks.
if not getattr(cls, '_is_runtime_protocol', False):
- if _allow_reckless_class_cheks():
+ if _allow_reckless_class_checks():
return NotImplemented
raise TypeError("Instance and class checks can only be used with"
" @runtime_checkable protocols")
if not _is_callable_members_only(cls):
- if _allow_reckless_class_cheks():
+ if _allow_reckless_class_checks():
return NotImplemented
raise TypeError("Protocols with non-method members"
" don't support issubclass()")
diff --git a/Misc/NEWS.d/next/Library/2021-05-12-16-43-21.bpo-38908.nM2_rO.rst b/Misc/NEWS.d/next/Library/2021-05-12-16-43-21.bpo-38908.nM2_rO.rst
new file mode 100644
index 0000000000000..b72936c205f67
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-05-12-16-43-21.bpo-38908.nM2_rO.rst
@@ -0,0 +1,5 @@
+Fix issue where :mod:`typing` protocols without the ``@runtime_checkable``
+decorator did not raise a ``TypeError`` when used with ``issubclass`` and
+``isinstance``. Now, subclassses of ``typing.Protocol`` will raise a
+``TypeError`` when used with with those checks.
+Patch provided by Yurii Karabas.
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