Observer Pattern

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class Channel:
	def __init__(self, name):
		self.name = name
		self.subscribers = []
 
	def subscribe(self, sub):
		self.subscribers.append(sub)
 
	def notify(self, event):
		for sub in self.subscribers:
			sub.send_notification(self.name, event)
 
from abc import ABC, abstractmethod
 
 
class Subscriber(ABC):
	@abstractmethod
	def send_notification(self, event):
		pass
 
class User(Subscriber):
	def __init__(self, name):
		self.name = name
 
#! 확인
	def send_notification(self, channel, event):
		print(f"{self.name} recieved notification from {channel}.{event}")
 
 
channel = Channel("Seol")
channel.subscribe(User("user1"))
channel.subscribe(User("user2"))
channel.subscribe(User("user3"))
 
channel.notify("New video released. Check it out!")