def announce(self):
    for client in self.clients:
        client.transport.write('10 seconds has passed\n')

def clientConnectionMade(self, client):
    self.clients.append(client)

def clientConnectionLost(self, client):
    self.clients.remove(client)
myfactory = MyFactory()
reactor.listenTCP(9000, myfactory)
reactor.run()
Периодический запуск функции в скрученном протоколе