simple echo server in python

echoserver.py

import socket
import threading

def accept_request(client):
    client.send('welcome to echo server\n')
    client.send('please input\n')
    while True:
        msg = client.recv(1024)
        if(msg == 'exit\r\n'):
            break
        client.send(msg)
    client.close()

def server_main():
    host = socket.gethostbyname('localhost')
    port = 12345

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind((host, port))
    sock.listen(1)
    print 'echo server running on port {0}'.format(port)
    while True:
        client, address = sock.accept()
        thread = threading.Thread(target = accept_request, args = (client,))
        thread.start()
    sock.close()