Observer Pattern in Python

Observer_Pattern.py

class Observable:
    def __init__(self):
        self.__observers = []
    
    def register_observer(self, observer):
        self.__observers.append(observer)
    
    def notify_observers(self, *args, **kwargs):
        for observer in self.__observers:
            observer.notify(self, *args, **kwargs)



class Observer:
    def __init__(self, observable):
        observable.register_observer(self)

    def notify(self, observable, *args, **kwargs):
        raise NotImplementedError

class Hex_Observer(Observer):
    def notify(self, observable, *args, **kwargs):
        print( "Hex value = %s" % hex(args[0]) )

class Binary_Observer(Observer):
    def notify(self, observable, *args, **kwargs):
        print( "Binary value = %s" % bin(args[0]) )

class Decimal_Observer(Observer):
    def notify(self, observable, *args, **kwargs):
        print( "Binary value = %s" % bin(args[0]) )


subject = Observable()

observer1 = Hex_Observer(subject)
observer2 = Binary_Observer(subject)
observer3 = Decimal_Observer(subject)

subject.notify_observers(100)