与c/c++ socket编程对照见http://blog.csdn.net/aspnet_lyc/article/details/38946915

server：

import socket

PORT    = 9999
BACKLOG = 5
MAXLINE = 1024

listenfd = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
listenfd.bind(('',PORT))
listenfd.listen(BACKLOG)

while True:
	connfd, connaddr = listenfd.accept()
	print 'a new connection'
	buf = []
	buf = connfd.recv(MAXLINE)
	print buf
	connfd.send('Hello,this is server')
	connfd.close()

import socket

addr = '127.0.0.1'
port = 9999
sockfd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sockfd.connect((addr, port))
sockfd.send('Hello,this is client')
buf = []

while True:
	recv_data = sockfd.recv(1024)
	if recv_data:
		buf.append(recv_data)
	else:
		break

data = ''.join(buf)
print data
sockfd.close()