python理解观察者模式（发布——订阅者模式）

# -*- coding: utf-8 -*- class Subject: def register(self, observer): pass def unregister(self, observer): pass def notify(self, msg): pass class Weather(Subject): def __init__(self): self.observers = [] def register(self, observer): if not observer in self.observers: self.observers.append(observer) def unregister(self, observer): self.observers.remove(observer) def notify(self, msg): for observer in self.observers: observer.do_something(msg) class Observer: def do_something(self, msg): pass class Ruhua(Observer): def do_something(self, msg): if '雨' in msg: print('下雨了，如花可以去桥边等伯虎了') elif '雪' in msg: print('下雪了，如花可以去堆雪人了') elif '太阳' in msg: print('出太阳了，如花要去网吧了') class Cuihua(Observer): def do_something(self, msg): if '雨' in msg: print('下雨了，翠花要做酸菜了') elif '雪' in msg: print('下雪了，翠花要喂雪人吃酸菜了') elif '太阳' in msg: print('出太阳了，翠花，上酸菜') class Cunhua(Observer): def do_something(self, msg): if '雨' in msg: print('下雨了，村花在赏雨') elif '雪' in msg: print('下雪了，村花在赏雪') elif '太阳' in msg: print('出太阳了，村花在日光浴') if __name__ == '__main__': ruhua = Ruhua() cuihua = Cuihua() cunhua = Cunhua() weather = Weather() weather.register(ruhua) weather.register(cuihua) weather.register(cunhua) weather.notify('下雨了') weather.notify('出太阳了') weather.notify('下雪了') # -*- coding: utf-8 -*- class Subject: def regist