https://github.com/python/cpython/commit/4036afb56a4c6ba97a2f1471961b97d8e257c416 commit: 4036afb56a4c6ba97a2f1471961b97d8e257c416 branch: main author: sobolevn <[email protected]> committer: ambv <[email protected]> date: 2026-10-21T15:53:04-07:00 summary:
gh-94808: add tests covering `PySequence_[InPlace]Concat` (#99319) Co-authored-by: Muse Code (Meta Muse Spark) Co-authored-by: Lukasz Langa <[email protected]> files: M Lib/test/test_operator.py diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py index 68c8aadeb50823..4da4eeb242e01c 100644 --- a/Lib/test/test_operator.py +++ b/Lib/test/test_operator.py @@ -560,6 +560,221 @@ def __getitem__(self, other): return 5 # so that C is a sequence self.assertEqual(operator.ixor (c, 5), "ixor") self.assertEqual(operator.iconcat (c, c), "iadd") + def test_concat_subclasses(self): + operator = self.module + + # Simple cases: + data1 = [1, 2] + data2 = ['a', 'b'] + self.assertEqual(operator.concat(data1, data2), [1, 2, 'a', 'b']) + self.assertEqual(operator.concat(data1, data2), data1 + data2) + self.assertEqual(data1, [1, 2]) # must not change + self.assertEqual(data2, ['a', 'b']) # must not change + + data1 = (1, 2) + data2 = ('a', 'b') + self.assertEqual(operator.concat(data1, data2), (1, 2, 'a', 'b')) + self.assertEqual(operator.concat(data1, data2), data1 + data2) + self.assertEqual(data1, (1, 2)) # must not change + self.assertEqual(data2, ('a', 'b')) # must not change + + data1 = '12' + data2 = 'ab' + self.assertEqual(operator.concat(data1, data2), '12ab') + self.assertEqual(operator.concat(data1, data2), data1 + data2) + self.assertEqual(data1, '12') # must not change + self.assertEqual(data2, 'ab') # must not change + + # Subclasses: + class ListSubclass(list): + pass + + data1 = ListSubclass([1, 2]) + data2 = ListSubclass(['a', 'b']) + res = operator.concat(data1, data2) + self.assertIs(type(res), list) + self.assertEqual(res, [1, 2, 'a', 'b']) + self.assertEqual(data1, ListSubclass([1, 2])) # must not change + self.assertEqual(data2, ListSubclass(['a', 'b'])) # must not change + + data1 = ListSubclass([1, 2]) + data2 = ['a', 'b'] + res = operator.concat(data1, data2) + self.assertIs(type(res), list) + self.assertEqual(res, [1, 2, 'a', 'b']) + self.assertEqual(data1, ListSubclass([1, 2])) # must not change + self.assertEqual(data2, ['a', 'b']) # must not change + + data1 = [1, 2] + data2 = ListSubclass(['a', 'b']) + res = operator.concat(data1, data2) + self.assertIs(type(res), list) + self.assertEqual(res, [1, 2, 'a', 'b']) + self.assertEqual(data1, [1, 2]) # must not change + self.assertEqual(data2, ListSubclass(['a', 'b'])) # must not change + + # Custom type with `__add__`: + class TupleSubclass(tuple): + def __add__(self, other): + return TupleSubclass(list(other) + list(self)) + + data1 = TupleSubclass([1, 2]) + data2 = TupleSubclass(['a', 'b']) + res = operator.concat(data1, data2) + self.assertIsInstance(res, TupleSubclass) + self.assertEqual(res, TupleSubclass(['a', 'b', 1, 2])) + self.assertEqual(data1, TupleSubclass([1, 2])) # must not change + self.assertEqual(data2, TupleSubclass(['a', 'b'])) # must not change + + data1 = TupleSubclass([1, 2]) + data2 = ('a', 'b') + res = operator.concat(data1, data2) + self.assertIsInstance(res, TupleSubclass) + self.assertEqual(res, TupleSubclass(['a', 'b', 1, 2])) + self.assertEqual(data1, TupleSubclass([1, 2])) # must not change + self.assertEqual(data2, ('a', 'b')) # must not change + + data1 = (1, 2) + data2 = TupleSubclass(['a', 'b']) + res = operator.concat(data1, data2) + self.assertIs(type(res), tuple) + self.assertEqual(res, (1, 2, 'a', 'b')) + self.assertEqual(data1, (1, 2)) # must not change + self.assertEqual(data2, TupleSubclass(['a', 'b'])) # must not change + + # Corner cases: + self.assertEqual(operator.concat([1, 2], []), [1, 2]) + self.assertEqual(operator.concat([], [1, 2]), [1, 2]) + self.assertEqual(operator.concat([], []), []) + + # Type errors: + self.assertRaises(TypeError, operator.concat, [], 1) + self.assertRaises(TypeError, operator.concat, 1, []) + self.assertRaises(TypeError, operator.concat, 1, 1) + self.assertRaises(TypeError, operator.concat, (), []) + self.assertRaises(TypeError, operator.concat, [], ()) + + # Returns `NotImplemented`: + class BrokenSeq(tuple): + def __add__(self, other): + return NotImplemented + + self.assertRaises(TypeError, operator.concat, BrokenSeq(), BrokenSeq()) + + def test_iconcat(self): + operator = self.module + + # Simple cases: + data1 = [1, 2, 3] + data2 = ['a', 'b'] + res = operator.iconcat(data1, data2) + self.assertEqual(res, [1, 2, 3, 'a', 'b']) + self.assertEqual(data1, [1, 2, 3, 'a', 'b']) # must change + self.assertEqual(data2, ['a', 'b']) # must not change + + data1 = (1, 2) + data2 = ('a', 'b') + self.assertEqual(operator.iconcat(data1, data2), (1, 2, 'a', 'b')) + self.assertEqual(operator.iconcat(data1, data2), data1 + data2) + self.assertEqual(data1, (1, 2)) # must not change + self.assertEqual(data2, ('a', 'b')) # must not change + + data1 = '12' + data2 = 'ab' + self.assertEqual(operator.iconcat(data1, data2), '12ab') + self.assertEqual(operator.iconcat(data1, data2), data1 + data2) + self.assertEqual(data1, '12') # must not change + self.assertEqual(data2, 'ab') # must not change + + # Subclasses: + class ListSubclass(list): + pass + + data1 = ListSubclass([1, 2]) + data2 = ListSubclass(['a', 'b']) + res = operator.iconcat(data1, data2) + self.assertIsInstance(res, ListSubclass) + self.assertEqual(res, ListSubclass([1, 2, 'a', 'b'])) + self.assertIsInstance(data1, ListSubclass) + self.assertEqual(data1, ListSubclass([1, 2, 'a', 'b'])) # must change + self.assertEqual(data2, ListSubclass(['a', 'b'])) # must not change + + data1 = ListSubclass([1, 2]) + data2 = ['a', 'b'] + res = operator.iconcat(data1, data2) + self.assertIsInstance(res, ListSubclass) + self.assertEqual(res, ListSubclass([1, 2, 'a', 'b'])) + self.assertIsInstance(data1, ListSubclass) + self.assertEqual(data1, ListSubclass([1, 2, 'a', 'b'])) # must change + self.assertEqual(data2, ['a', 'b']) # must not change + + data1 = [1, 2] + data2 = ListSubclass(['a', 'b']) + res = operator.iconcat(data1, data2) + self.assertIs(type(res), list) + self.assertEqual(res, [1, 2, 'a', 'b']) + self.assertIs(type(data1), list) + self.assertEqual(data1, [1, 2, 'a', 'b']) # must change + self.assertEqual(data2, ListSubclass(['a', 'b'])) # must not change + + # Custom type with `__add__`: + class TupleSubclass(tuple): + def __add__(self, other): + return TupleSubclass(list(other) + list(self)) + + data1 = TupleSubclass([1, 2]) + data2 = TupleSubclass(['a', 'b']) + res = operator.iconcat(data1, data2) + self.assertIsInstance(res, TupleSubclass) + self.assertEqual(res, TupleSubclass(['a', 'b', 1, 2])) + self.assertEqual(data1, TupleSubclass([1, 2])) # must not change + self.assertEqual(data2, TupleSubclass(['a', 'b'])) # must not change + + data1 = TupleSubclass([1, 2]) + data2 = ('a', 'b') + res = operator.iconcat(data1, data2) + self.assertIsInstance(res, TupleSubclass) + self.assertEqual(res, TupleSubclass(['a', 'b', 1, 2])) + self.assertEqual(data1, TupleSubclass([1, 2])) # must not change + self.assertEqual(data2, ('a', 'b')) # must not change + + data1 = (1, 2) + data2 = TupleSubclass(['a', 'b']) + res = operator.iconcat(data1, data2) + self.assertIs(type(res), tuple) + self.assertEqual(res, TupleSubclass([1, 2, 'a', 'b'])) + self.assertEqual(data1, (1, 2)) # must not change + self.assertEqual(data2, TupleSubclass(['a', 'b'])) # must not change + + # Corner cases: + self.assertEqual(operator.iconcat([1, 2], []), [1, 2]) + self.assertEqual(operator.iconcat([], [1, 2]), [1, 2]) + self.assertEqual(operator.iconcat([], []), []) + self.assertEqual(operator.iconcat([], ()), []) + + # Type errors: + self.assertRaises(TypeError, operator.iconcat, [], 1) + self.assertRaises(TypeError, operator.iconcat, 1, []) + self.assertRaises(TypeError, operator.iconcat, 1, 1) + self.assertRaises(TypeError, operator.iconcat, (), []) + + # Returns `NotImplemented`: + class BrokenSeq1(list): + def __add__(self, other): + return NotImplemented + def __iadd__(self, other): + return NotImplemented + + self.assertRaises(TypeError, + operator.iconcat, BrokenSeq1(), BrokenSeq1()) + + class BrokenSeq2(tuple): + def __add__(self, other): + return NotImplemented + + self.assertRaises(TypeError, + operator.iconcat, BrokenSeq2(), BrokenSeq2()) + def test_iconcat_without_getitem(self): operator = self.module _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
