Question

I am in the process of designing some hardware interface with python. what I need to do is as follows,

~initialize the drivers
~start the device
~create a socket at port 2626 and wait for clients to connect for receiving data
~if any client got connected then send the hello message while serving all other connected client and add this client to the connected client list.
~if any event happened on the device lets say temperature raise is detected then through this event data to all connected clients.
~any connected clients can ask the server for any specific data.

This is my process. I got the device part working great now its printing data to console and for the socket server I have this following code this working fine as I expect.
but what is problem is after calling “run()” its going inside the while loop. its obvious though. when I am listening for new connections I am not able to call any other function.

while listening for connections I should be able to send / recv. any ideas how to do this?

this is my server program which is working fine for listening for connections. while listening you are not allowed to to anything. 🙁

#!/usr/bin/env python

import socket
import select

class ChatServer:

    def __init__( self, port ):
        self.port = port;

        self.srvsock = socket.socket( socket.AF_INET, socket.SOCK_STREAM )
        self.srvsock.setsockopt( socket.SOL_SOCKET, socket.SO_REUSEADDR, 1 )
        self.srvsock.bind( ("", port) )
        self.srvsock.listen( 5 )

        self.descriptors = [self.srvsock]
        print 'Server started on port %s' % port

    def run( self ):
        while 1:
            # Await an event on a readable socket descriptor
            (sread, swrite, sexc) = select.select( self.descriptors, [], [] )
            # Iterate through the tagged read descriptors
            for sock in sread:
                # Received a connect to the server (listening) socket
                if sock == self.srvsock:
                    self.accept_new_connection()
                else:
                    # Received something on a client socket
                    str = sock.recv(100)

                    # Check to see if the peer socket closed
                    if str == '':
                        host,port = sock.getpeername()
                        str = 'Client left %s:%s\r\n' % (host, port)
                        self.broadcast_string( str, sock )
                        sock.close
                        self.descriptors.remove(sock)
                    else:
                        host,port = sock.getpeername()
                        newstr = '[%s:%s] %s' % (host, port, str)
                        self.broadcast_string( newstr, sock )

    def accept_new_connection( self ):
        newsock, (remhost, remport) = self.srvsock.accept()
        self.descriptors.append( newsock )

        newsock.send("You're connected to the Python server\r\n")
        str = 'Client joined %s:%s\r\n' % (remhost, remport)
        self.broadcast_string( str, newsock )

    def broadcast_string( self, str, omit_sock ):
        for sock in self.descriptors:
            if sock != self.srvsock and sock != omit_sock:
                sock.send(str)
        print str,

myServer = ChatServer( 2626 ).run()

Thanks in advance for all your help 🙂

Answer 1

Since twisted is out of question, I suggest using the socketserver module.

For an easy start, see this example.