test_weakref.py 文件源码

def test_weak_keys_destroy_while_iterating(self):
        # Issue #7105: iterators shouldn't crash when a key is implicitly removed
        dict, objects = self.make_weak_keyed_dict()
        self.check_weak_destroy_while_iterating(dict, objects, 'keys')
        self.check_weak_destroy_while_iterating(dict, objects, 'items')
        self.check_weak_destroy_while_iterating(dict, objects, 'values')
        self.check_weak_destroy_while_iterating(dict, objects, 'keyrefs')
        dict, objects = self.make_weak_keyed_dict()
        @contextlib.contextmanager
        def testcontext():
            try:
                it = iter(dict.items())
                next(it)
                # Schedule a key/value for removal and recreate it
                v = objects.pop().arg
                gc.collect()      # just in case
                yield Object(v), v
            finally:
                it = None           # should commit all removals
                gc.collect()
        self.check_weak_destroy_and_mutate_while_iterating(dict, testcontext)