如何在继承自另一个构造函数类方法中添加更多信息，而不用新的信息替换该信息？

class ParentClass:
    def __init__(self, info):
        self.info = info

    def get_info(self):
        return self.info


class ChildClass(ParentClass):
    def __init__(self, info, extra_info):
        super().__init__(info)
        self.extra_info = extra_info

    def get_extra_info(self):
        return self.extra_info


parent_obj = ParentClass("父类信息")
print(parent_obj.get_info())

child_obj = ChildClass("子类信息", "额外信息")
print(child_obj.get_info())
print(child_obj.get_extra_info())