pip install python-patterns
python
from observer import Subject, Observer
class ConcreteObserver(Observer):
def update(self, subject):
class ConcreteSubject(Subject):
def __init__(self):
self.state = None
class ConcreteObserverB(Observer):
def update(self, subject):
class ConcreteSubjectB(Subject):
def __init__(self):
self.state = None
if __name__ == "__main__":
subject = ConcreteSubject()
observerA = ConcreteObserver()
observerB = ConcreteObserverB()
subject.attach(observerA)
subject.attach(observerB)
subject.notify()
