class Main(object): def __init__(self, username, passwords): self.username = username self.passwords = json.dumps(passwords).encode("utf-8") self.client = EtcdClient(reactor) reactor.callWhenRunning(self.setPasswords) def setPasswords(self): d = self.client.set("/secant/users/{}/passwords".format(self.username), value=self.passwords) d.addCallback(self.finish) def finish(self, result): reactor.stop()