class A:
    __instance = None
    def __init__(self, name):
        self.name = name

    # @classmethod
    # def __new__(cls, *args, **kwargs):
    #     print("开始new新对象")
    #     # if not A.__new__(cls):
    #     #     cls = A.__new__()
    #     return object.__new__(cls)
    # @classmethod
    # def get_instance(cls, name):
    #     if not cls.__instance:
    #         cls.__instance = A(name)
    #     return cls.__instance
    @classmethod
    def __new__(cls, name, *args, **kwargs):
        if not cls.__instance:
            cls.__instance = object.__new__(name)
        return cls.__instance
    def __str__(self):
        return "name : %s"%self.name

a = A("zhangsan")
b = A("lisi")
print(a == b)
print(id(a))
print(id(b))