python asynchat: how to store information on individual connections, and how to know when a client disconnects

For fun, I'm writing a minimal IRC server with asynchat. I'm trying to clear up a few fundamentals (my specific questions follow the code). I've decided not to use anything in Twisted just so I can implement a little more myself. First, the code I have:

import asyncore,asynchat
import socket

class Connection(asynchat.async_chat):
    def __init__(self, server, sock, addr):
        asynchat.async_chat.__init__(self, sock)
        self.set_terminator('\n')
        self.data = ""
        print "client connecting:",addr
        # do some IRC protocol initialization stuff here

    def colle开发者_JAVA技巧ct_incoming_data(self, data):
        self.data = self.data + data

    def found_terminator(self):
        print self.data
        self.data = ''

class Server(asyncore.dispatcher):
    def __init__(self, host, port):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.bind((host, port))
        self.listen(5)

    def handle_accept(self):
        conn, addr = self.accept()
        Connection(self, conn, addr)

    def handle_close(self):
        self.close()

s = Server('127.0.0.1',5006)
asyncore.loop()

So, in my mind, this code structure is similar to a Twisted client factory: the Server class is initialized once and basically instantiates Connection every time a client connects. First question: is the best way to keep track of all connected clients by storing all of the Connections in a list within Server?

Also, I don't understand how I am to know when a specific client closes their connection to my socket? Connection implements asynchat (and by extension asyncore) but adding the handle_close() callback to the Connection class doesn't fire when a client disconnects. It seems to be only for when the bound socket on the server is destroyed. I don't see any methods for this purpose. This socket always stays open, whether or not clients connect, right?

to handle client side closed connections check the handle_error method, does your client issue a clean close connection? handle_error() :Called when an exception is raised and not otherwise handled. The default version prints a condensed traceback.

hope it helps.