ObserverPrototypeImplementation.py

class ObservableEvent:
    def __init__(self):
        self.__observers = []
    def register_observer(self, observer):
        self.__observers.append(observer)
    def de_register_observer(self, observer):
        self.__observers.remove(observer)
    def notify(self, *args, **kwargs):
        for observer in self.__observers:
            observer.trigger(*args, **kwargs)

class BaseObserver:
    def __init__(self, *args, **kwargs):
        observable.register_observer(self)
    def trigger(self, *args, **kwargs):
        print ("Invoked "+self.__class__.__name__+" with arguments ", args, kwargs)

class GenericObserver(BaseObserver):
    def __init__(self, observable):
        super(GenericObserver, self).__init__(observable)

class LoggerObserver(BaseObserver):
    def __init__(self, observable):
        super(LoggerObserver, self).__init__(observable)

class EmailerObserver(BaseObserver):
    def __init__(self, observable):
        super(EmailerObserver, self).__init__(observable)        

class WhatsApperObserver(BaseObserver):
    def __init__(self, observable):
        super(WhatsApperObserver, self).__init__(observable)        


if __name__ == '__main__':
    observable = ObservableEvent()
    gen_obs_1 = GenericObserver(observable)
    print ("Test Single Observer [Generic]")
    observable.notify("Hello", "World", "Test", "Generic")
    print ("Test Multiple Observers [Generic, Logger, Email, WhatsApp]")
    log_obs_1 = LoggerObserver(observable)
    email_obs_1 = EmailerObserver(observable)
    whatsapp_obs_1 = WhatsApperObserver(observable)
    observable.notify("Hello", "World", "Test", "Multiple")
    print ("Test after removing Generic observer")
    observable.de_register_observer(gen_obs_1)
    observable.notify("Hello", "World", "Test", "Multiple")