test_richcmp.py 文件源码

def test_recursion(self):
        # Check that comparison for recursive objects fails gracefully
        from UserList import UserList
        a = UserList()
        b = UserList()
        a.append(b)
        b.append(a)
        self.assertRaises(RuntimeError, operator.eq, a, b)
        self.assertRaises(RuntimeError, operator.ne, a, b)
        self.assertRaises(RuntimeError, operator.lt, a, b)
        self.assertRaises(RuntimeError, operator.le, a, b)
        self.assertRaises(RuntimeError, operator.gt, a, b)
        self.assertRaises(RuntimeError, operator.ge, a, b)

        b.append(17)
        # Even recursive lists of different lengths are different,
        # but they cannot be ordered
        self.assertTrue(not (a == b))
        self.assertTrue(a != b)
        self.assertRaises(RuntimeError, operator.lt, a, b)
        self.assertRaises(RuntimeError, operator.le, a, b)
        self.assertRaises(RuntimeError, operator.gt, a, b)
        self.assertRaises(RuntimeError, operator.ge, a, b)
        a.append(17)
        self.assertRaises(RuntimeError, operator.eq, a, b)
        self.assertRaises(RuntimeError, operator.ne, a, b)
        a.insert(0, 11)
        b.insert(0, 12)
        self.assertTrue(not (a == b))
        self.assertTrue(a != b)
        self.assertTrue(a < b)