# Read username, output from non-empty factory, drop connections # Use deferreds, to minimize synchronicity assumptions from twisted.internet import protocol, reactor, defer from twisted.protocols import basic class FingerProtocol(basic.LineReceiver): def lineReceived(self, user): self.factory.getUser(user ).addErrback(lambda _: "Internal error in server" ).addCallback(lambda m: (self.transport.write(m+"\r\n"), self.transport.loseConnection())) class FingerFactory(protocol.ServerFactory): protocol = FingerProtocol def __init__(self, **kwargs): self.users = kwargs def getUser(self, user): return defer.succeed(self.users.get(user, "No such user")) reactor.listenTCP(1079, FingerFactory(moshez='Happy and well')) reactor.run()