test_builtin.py 文件源码

def test_cmp(self):
        self.assertEqual(cmp(-1, 1), -1)
        self.assertEqual(cmp(1, -1), 1)
        self.assertEqual(cmp(1, 1), 0)
        # verify that circular objects are not handled
        a = []; a.append(a)
        b = []; b.append(b)
        from UserList import UserList
        c = UserList(); c.append(c)
        self.assertRaises(RuntimeError, cmp, a, b)
        self.assertRaises(RuntimeError, cmp, b, c)
        self.assertRaises(RuntimeError, cmp, c, a)
        self.assertRaises(RuntimeError, cmp, a, c)
       # okay, now break the cycles
        a.pop(); b.pop(); c.pop()
        self.assertRaises(TypeError, cmp)