How do you you run a Twisted application via Python (instead of via Twisted)?

Question

I am working my way through learning Twisted, and have stumbled across something I'm not sure I'm terribly fond of - the "Twisted Command Prompt". I am fiddling around with Twisted on my Windows machine, and tried running the "Chat" example:

from twisted.protocols import basic

class MyChat(basic.LineReceiver):
    def connectionMade(self):
        print "Got new client!"
        self.factory.clients.append(self)

    def connectionLost(self, reason):
        print "Lost a client!"
        self.factory.clients.remove(self)

    def lineReceived(self, line):
        print "received", repr(line)
        for c in self.factory.clients:
            c.message(line)

    def message(self, message):
        self.transport.write(message + '\n')


from twisted.internet import protocol
from twisted.application import service, internet

factory = protocol.ServerFactory()
factory.protocol = MyChat
factory.clients = []

application = service.Application("chatserver")
internet.TCPServer(1025, factory).setServiceParent(application)

However, to run this application as a Twisted server, I have to run it via the "Twisted Command Prompt", with the command:

twistd -y chatserver.py

Is there any way to change the code (set Twisted configuration settings, etc) so that I can simply run it via:

python chatserver.py

I've Googled, but the search terms seem to be too vague to return any meaningful responses.

Thanks.

Answer 1

I don't know if it's the best way to do this but what I do is instead of:

application = service.Application("chatserver")
internet.TCPServer(1025, factory).setServiceParent(application)

you can do:

from twisted.internet import reactor
reactor.listenTCP(1025, factory)
reactor.run()

Sumarized if you want to have the two options (twistd and python):

if __name__ == '__main__':
    from twisted.internet import reactor
    reactor.listenTCP(1025, factory)
    reactor.run()
else:
    application = service.Application("chatserver")
    internet.TCPServer(1025, factory).setServiceParent(application)

Hope it helps!

Answer 2

Don't confuse "Twisted" with "twistd". When you use "twistd", you are running the program with Python. "twistd" is a Python program that, among other things, can load an application from a .tac file (as you're doing here).

The "Twisted Command Prompt" is a Twisted installer-provided convenience to help out people on Windows. All it is doing is setting %PATH% to include the directory containing the "twistd" program. You could run twistd from a normal command prompt if you set your %PATH% properly or invoke it with the full path.

If you're not satisfied with this, perhaps you can expand your question to include a description of the problems you're having when using "twistd".