使用Select的Python套接字检查数据

Question

I found the following code on another post that works pretty good:

UDP_IP = ''
UDP_PORT = 5008
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('', UDP_PORT))
while 1:
  socket_list = [sys.stdin, s]
  # Get the list sockets which are readable
  read_sockets, write_sockets, error_sockets = select.select(socket_list , [], [])
  for sock in read_sockets:
   #incoming message from remote server
   if sock == s:
      data = sock.recv(4096)
      if not data :
        print '\nDisconnected from server'
        sys.exit()
      else :
         #print data
         sys.stdout.write(data)

   #user entered a message
   else :
     msg = sys.stdin.readline()
     s.send(msg)

The problem I've got is with the for loop since it only runs through it when there is data received. I would really like it to use a while loop and have it occasionally check on if data has been received but I can't figure out how to do this.

Answer 1

Use the timeout parameter in the select statement. If no data is available (indicated by empty lists), you can do whatever other processing is needed in the body of the while loop.