#!/usr/bin/env python  # UDP Echo Server -  udpserver.py  import socket, traceback  host = ''  port = 54321  s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)  s.bind((host, port))  while 1:      try:          message, address = s.recvfrom(8192)          print "Got data from", address, ": ", message          s.sendto(message, address)      except (KeyboardInterrupt, SystemExit):          raise      except:          traceback.print_exc()  

1 #!/usr/bin/env python  # UDP Client - udpclient.py  import socket, sys  host = sys.argv[1]  textport = sys.argv[2]  s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  try:      port = int(textport)  except ValueError:      port = socket.getservbyname(textport, 'udp')  s.connect((host, port))  while 1:      print "Enter data to transmit:"      data = sys.stdin.readline().strip()      s.sendall(data)      print "Looking for replies; press Ctrl-C or Ctrl-Break to stop."      buf = s.recv(2048)      if not len(buf):          break      print "Server replies: ",      sys.stdout.write(buf)      print "\n"