Python设计模式中的备忘录模式

class AddNumber:
    def __init__(self):
        self.start = 1
    def add(self, number):
        self.start += number
        print(self.start)

class Memento:
    """备忘录"""
    def backups(self, obj=None):
        """
        设置备份方法
        :param obj: 
        :return: 
        """
        self.obj_dict = copy.deepcopy(obj.__dict__)
        print("备份数据:{}".fORMat(self.obj_dict))
    def recovery(self, obj):
        """
        恢复备份方法
        :param obj: 
        :return: 
        """
        obj.__dict__.clear()
        obj.__dict__.update(self.obj_dict)
        return obj

if __name__ == '__main__':
    test = AddNumber()
    memento = Memento()
    for i in [1, 2, 3, 'n', 4]:
        if i == 2:
            memento.backups(test)
        try:
            test.add(i)
        except TypeError as e:
            print(e)
            print(test.start)
    memento.recovery(test)
    print(test.start)