# -*- coding: utf-8 -*-
# 主题
class Subject(object):
    def __init__(self):
        self.__observers = []
    def register(self, observer):
        self.__observers.append(observer)
    def notify_all(self, message):
        for observer in self.__observers:
            observer.notify(self, message)
from abc import ABC, abstractmethod
# 观察者
class IObserver(ABC):
    @abstractmethod
    def notify(self, subject, message):
        pass
# 具体观察者
class Observer1(IObserver):
    def notify(self, subject, message):
        print("Observer1 收到{}主题消息: {}".format(type(subject).__name__, message))
class Observer2(IObserver):
    def notify(self, subject, message):
        print("Observer2 收到{}主题消息: {}".format(type(subject).__name__, message))
if __name__ == '__main__':
    observer1 = Observer1()
    observer2 = Observer2()
    subject = Subject()
    subject.register(observer1)
    subject.register(observer2)
    subject.notify_all("通知：3：00开会")
    """
    Observer1 收到Subject主题消息: 通知：3：00开会
    Observer2 收到Subject主题消息: 通知：3：00开会
    """