python - Client-Server socket setup, how to respond to a determined client -

this question has been edited focus in simpler problem

so have basic client-server socket installation, in client send json {'id': '1', 'value': 'a'}. @ server side, if receive message id 2 want send message client id 1, telling him new value c.

this message should "private", i.e., id 1 should receive it, no broadcasting allowed.

how should approach problem? how keep track of connections @ server side send message determined client? problem it's server 1 sending message client, not responding client's message. guess must combination of threading , queues, still haven't figured out how it.

this code have right @ server, keeping track of clients using dict, it's not working (bad file descriptor @ sendall('c') line:

track_clients = {} while true:     print "waiting connection"     connection, client_address = sock.accept()     try:         print "connection ", client_address         data = json.loads(connection.recv(1024))         track_clients[data['id']] = connection          if data['id'] == '2':             conn = track_clients['1']             conn.sendall('c')         connection.sendall(json.dumps(data))     finally:         connection.close() 

you can have @ channels http://channels.readthedocs.org/en/latest/. alongside redis (https://pypi.python.org/pypi/redis/)