"""Utilities for with-statement contexts. See PEP 343."""
import abc
import sys
+import _collections_abc
from collections import deque
from functools import wraps
@classmethod
def __subclasshook__(cls, C):
if cls is AbstractContextManager:
- if (any("__enter__" in B.__dict__ for B in C.__mro__) and
- any("__exit__" in B.__dict__ for B in C.__mro__)):
- return True
+ return _collections_abc._check_methods(C, "__enter__", "__exit__")
return NotImplemented
self.assertTrue(issubclass(DefaultEnter, AbstractContextManager))
+ class NoEnter(ManagerFromScratch):
+ __enter__ = None
+
+ self.assertFalse(issubclass(NoEnter, AbstractContextManager))
+
+ class NoExit(ManagerFromScratch):
+ __exit__ = None
+
+ self.assertFalse(issubclass(NoExit, AbstractContextManager))
+
class ContextManagerTestCase(unittest.TestCase):
- bpo-30048: Fixed ``Task.cancel()`` can be ignored when the task is
running coroutine and the coroutine returned without any more ``await``.
+- bpo-30266: contextlib.AbstractContextManager now supports anti-registration
+ by setting __enter__ = None or __exit__ = None, following the pattern
+ introduced in bpo-25958. Patch by Jelle Zijlstra.
+
- bpo-30340: Enhanced regular expressions optimization. This increased
the performance of matching some patterns up to 25 times.