python 如果在上次调用属性后属性发生了变化，则该类只应重建某些内容。

Posted 2021-05-10

class Test:
    
    def __init__(self):
        self.a1 = 1
        self.a2 = 2
        self.a3 = 3
        self.__dict__['update_flag'] = False
    
    def __setattr__(self, name, value):
        self.__dict__['update_flag'] = True
        self.__dict__[name] = value

    def run(self):
        if self.update_flag:
            print('updating ...')
            self.__dict__['update_flag'] = False
        print('running ...')