echoserver.py

#!/usr/bin/env python
from __future__ import print_function

import sys
import time

try:
    import socketserver
except ImportError:
    import SocketServer as socketserver


class MyTCPHandler(socketserver.StreamRequestHandler):

    def handle(self):
        if sleep_time is not None:
            time.sleep(sleep_time)
        while True:
            data = self.rfile.readline().strip()
            print("{} wrote:".format(self.client_address[0]))
            print(data)
            resp = data.upper() + '\n'
            self.wfile.write(resp)


if __name__ == "__main__":
    if len(sys.argv) < 3:
        print('Usage: %s BIND_HOST BIND_PORT [SLEEP_TIME]' % (sys.argv[0],))
        sys.exit(1)
    host = sys.argv[1]
    port = int(sys.argv[2])

    global sleep_time
    sleep_time = None
    if len(sys.argv) >= 4:
        sleep_time = int(sys.argv[3])

    socketserver.TCPServer.allow_reuse_address = True
    server = socketserver.TCPServer((host, port), MyTCPHandler)
    print('Listening on %s:%d...' % (host, port))
    server.serve_forever()