python网络基础学习笔记：一个简单的server

#! /usr/bin/env python
import socket, sys

host = 'localhost'
port = 54321

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))

s.listen(1)

print "Server is running in port %d" % port
while 1:
    clientsock, clientaddr = s.accept()
    clientfile = clientsock.makefile('rw', 0)
    clientfile.write("Welcome, " + str(clientaddr) +  '\n')
    clientfile.write("Please enter a string: ")
    line = clientfile.readline().strip()
    clientfile.write("You entered %d characters.\n" % len(line))
    clientfile.close()
    clientsock.close()