Python 观察者模式示例

"""
观察者模式
"""


class Observer:

    def update(self, notice):
        pass


class Notice:
    def __init__(self):
        self.observers = []

    def attach(self, obs: Observer):
        self.observers.append(obs)

    def detach(self, obs: Observer):
        self.observers.remove(obs)

    def notify(self):
        for obs in self.observers:
            obs.update(self)


class StaffNotice(Notice):

    def __init__(self, company_info):
        super().__init__()
        self.__company_info = company_info

    @property
    def company_info(self):
        return self.__company_info

    @company_info.setter
    def company_info(self, info):
        self.__company_info = info
        self.notify()


class Staff(Observer):

    def __init__(self):
        self.company_info = None

    def update(self, notice: StaffNotice):
        self.company_info = notice.company_info


staff_notice = StaffNotice("初始化公司信息")
staff1 = Staff()
staff2 = Staff()
staff_notice.attach(staff1)
staff_notice.attach(staff2)
staff_notice.company_info = "假期放假通知！"
print(staff1.company_info)
print(staff2.company_info)