test_abc.py 文件源码

def test_registration_builtins(self):
        class A(metaclass=abc.ABCMeta):
            pass
        A.register(int)
        self.assertIsInstance(42, A)
        self.assertIsInstance(42, (A,))
        self.assertTrue(issubclass(int, A))
        self.assertTrue(issubclass(int, (A,)))
        class B(A):
            pass
        B.register(str)
        class C(str): pass
        self.assertIsInstance("", A)
        self.assertIsInstance("", (A,))
        self.assertTrue(issubclass(str, A))
        self.assertTrue(issubclass(str, (A,)))
        self.assertTrue(issubclass(C, A))
        self.assertTrue(issubclass(C, (A,)))