test_weakref.py 文件源码

def test_getweakrefcount(self):
        o = C()
        ref1 = weakref.ref(o)
        ref2 = weakref.ref(o, self.callback)
        self.assertTrue(weakref.getweakrefcount(o) == 2,
                     "got wrong number of weak reference objects")

        proxy1 = weakref.proxy(o)
        proxy2 = weakref.proxy(o, self.callback)
        self.assertTrue(weakref.getweakrefcount(o) == 4,
                     "got wrong number of weak reference objects")

        del ref1, ref2, proxy1, proxy2
        self.assertTrue(weakref.getweakrefcount(o) == 0,
                     "weak reference objects not unlinked from"
                     " referent when discarded.")

        # assumes ints do not support weakrefs
        self.assertTrue(weakref.getweakrefcount(1) == 0,
                     "got wrong number of weak reference objects for int")