socket可以实现网络上，两个程序的通信实现数据交换。

客户端

实现以下工作：

• 创建socket
• 建立连接
• 收发数据

# -*- coding:utf-8 -*-

import socket
import sys  #for exit

try:
    #create an AF_INET, STREAM socket (TCP)
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    #socket()两个参数 Address Family: 可以选择AF_INET(用于Internet进程间通信)，AF_UNIX(用于同一台机器进程间通信)
    #Type :可以选择SOCKET_STREAM(流式套接字，主要用于TCP),SOCKET_DGRAM(数据报套接字，用于UDP)
except socket.error, msg:   #错误处理
    print 'Failed to create socket. Error code: ' + str(msg[0]) + ', Error message :' + msg[1]
    sys.exit()

print 'Socket Created'

host = 'www.baidu.com'
port = 80
try:
    remote_ip = socket.gethostbyname(host)      #获取ip
except socket.gaierror:
    #could not resolve
    print 'Hostname could not be resolved. Exiting'
    sys.exit()

print 'Ip address of' + host + ' is ' + remote_ip

#Connect to remote server
s.connect((remote_ip, port))            #进行连接

print 'Socket connected to ' + host + ' on ip ' + remote_ip

#Send some data to remote server
message= "GET / HTTP/1.1\r\n\r\n"

try:
    s.sendall(message)       #发送数据  
except socket.error:
    print 'Send failed'
    sys.exit()

print 'Message send successfully'

#Now receive data
reply = s.recv(4096)  #接受长度为4096字节的数据

print reply

s.close()

执行结果

服务端

实现以下工作：

• 创建socket
• 绑定socket到特定的地址及端口
• 监听连接
• 建立连接
• 接发数据

要实现多个用户连接并且发送多条数据，需要用到线程。
code:

# -*- coding:utf-8 -*-

import socket
import sys
from thread import *

HOST = ''
PORT = 8888

s =socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'

try:
    s.bind((HOST, PORT)) #绑定socket 到地址和端口上
except socket.error, msg:
    print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
    sys.exit()

print 'Socket blind complete'

s.listen(10)       #进行监听
print 'Socket now listening'

#Function for handling connections. This will be used to create threads
def clientthread(conn):
    #Sending message to connected client
    conn.send('Welcome to the server. Type somthing and hit enter\n') #send only takes string

    #infinite loop so that function do not terminate and thread do not end
    while True:
        #Receiving from client
        data = conn.recv(1024)
        if not data:
            break

        print addr[0] + ':' + str(addr[1]) + ' say:' + data
        conn.sendall(data)

#now keep talking whith the client
while 1:
    #wait to accept a connection - blocking call
    conn, addr = s.accept()

    #display client informaiton
    print 'Connected with ' + addr[0] + ':' + str(addr[1])

    #start new thread takes 1st argument as a function name to be run, second is the tuple of arguments to the function
    start_new_thread(clientthread, (conn,))

s.close()

执行结果



可以由多个终端连接，并且可以发送多条信息。