如何在元组上定义后缀运算符？

class MyTuple:
    def __init__(self, values):
        self.values = values

    def __str__(self):
        return str(self.values)

    def __add__(self, other):
        if isinstance(other, MyTuple):
            new_values = self.values + other.values
            return MyTuple(new_values)
        else:
            raise ValueError("Unsupported operand type.")

    def __sub__(self, other):
        if isinstance(other, MyTuple):
            new_values = [x for x in self.values if x not in other.values]
            return MyTuple(new_values)
        else:
            raise ValueError("Unsupported operand type.")

# 示例用法
tuple1 = MyTuple((1, 2, 3))
tuple2 = MyTuple((3, 4, 5))
tuple3 = tuple1 + tuple2  # 调用 __add__ 方法
tuple4 = tuple1 - tuple2  # 调用 __sub__ 方法

print(tuple3)  # 输出: (1, 2, 3, 3, 4, 5)
print(tuple4)  # 输出: (1, 2)