test_copy.py 文件源码

def test_deepcopy_weakvaluedict(self):
        class C(object):
            def __init__(self, i):
                self.i = i
        a, b, c, d = [C(i) for i in range(4)]
        u = weakref.WeakValueDictionary()
        u[a] = b
        u[c] = d
        # Keys are copied, values aren't
        v = copy.deepcopy(u)
        self.assertNotEqual(v, u)
        self.assertEqual(len(v), 2)
        (x, y), (z, t) = sorted(v.items(), key=lambda pair: pair[0].i)
        self.assertIsNot(x, a)
        self.assertEqual(x.i, a.i)
        self.assertIs(y, b)
        self.assertIsNot(z, c)
        self.assertEqual(z.i, c.i)
        self.assertIs(t, d)
        del x, y, z, t
        del d
        self.assertEqual(len(v), 1)