diff options
| -rw-r--r-- | Lib/_abcoll.py | 7 | ||||
| -rw-r--r-- | Lib/test/test_collections.py | 25 | ||||
| -rw-r--r-- | Misc/NEWS | 2 |
3 files changed, 30 insertions, 4 deletions
diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py index 45747a6..7b01178 100644 --- a/Lib/_abcoll.py +++ b/Lib/_abcoll.py @@ -320,10 +320,9 @@ class MutableSet(Set): self.add(value) return self - def __iand__(self, c: Container): - for value in self: - if value not in c: - self.discard(value) + def __iand__(self, it: Iterable): + for value in (self - it): + self.discard(value) return self def __ixor__(self, it: Iterable): diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py index 3d00973..e8d72ee 100644 --- a/Lib/test/test_collections.py +++ b/Lib/test/test_collections.py @@ -327,6 +327,25 @@ class TestOneTrickPonyABCs(ABCTestCase): B.register(C) self.failUnless(issubclass(C, B)) +class WithSet(MutableSet): + + def __init__(self, it=()): + self.data = set(it) + + def __len__(self): + return len(self.data) + + def __iter__(self): + return iter(self.data) + + def __contains__(self, item): + return item in self.data + + def add(self, item): + self.data.add(item) + + def discard(self, item): + self.data.discard(item) class TestCollectionABCs(ABCTestCase): @@ -363,6 +382,12 @@ class TestCollectionABCs(ABCTestCase): self.validate_abstract_methods(MutableSet, '__contains__', '__iter__', '__len__', 'add', 'discard') + def test_issue_5647(self): + # MutableSet.__iand__ mutated the set during iteration + s = WithSet('abcd') + s &= WithSet('cdef') # This used to fail + self.assertEqual(set(s), set('cd')) + def test_issue_4920(self): # MutableSet.pop() method did not work class MySet(collections.MutableSet): @@ -55,6 +55,8 @@ Core and Builtins Library ------- +- Issue #5647: MutableSet.__iand__() no longer mutates self during iteration. + - Issue #5624: Fix the _winreg module name still used in several modules. - Issue #5628: Fix io.TextIOWrapper.read() with a unreadable buffer. |