test_weakref.py 文件源码

def test_weak_values(self):
        #
        #  This exercises d.copy(), d.items(), d[], del d[], len(d).
        #
        dict, objects = self.make_weak_valued_dict()
        for o in objects:
            self.assertEqual(weakref.getweakrefcount(o), 1)
            self.assertTrue(o is dict[o.arg],
                         "wrong object returned by weak dict!")
        items1 = list(dict.items())
        items2 = list(dict.copy().items())
        items1.sort()
        items2.sort()
        self.assertEqual(items1, items2,
                     "cloning of weak-valued dictionary did not work!")
        del items1, items2
        self.assertEqual(len(dict), self.COUNT)
        del objects[0]
        gc_collect()
        self.assertEqual(len(dict), self.COUNT - 1,
                     "deleting object did not cause dictionary update")
        del objects, o
        gc_collect()
        self.assertEqual(len(dict), 0,
                     "deleting the values did not clear the dictionary")
        # regression on SF bug #447152:
        dict = weakref.WeakValueDictionary()
        self.assertRaises(KeyError, dict.__getitem__, 1)
        dict[2] = C()
        gc_collect()
        self.assertRaises(KeyError, dict.__getitem__, 2)