# -*- coding: utf-8 -*-
import socket
print "Creating socket"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print "Done!\n"
print ‘Looking up port number...‘
port = socket.getservbyname(‘http‘,‘tcp‘)
print port
print "Done\n"
print "Connecting to remote host..."
s.connect(("www.baidu.com", port))
print "Done\n"
print "Conneted from",s.getsockname() #获得本地机器的ip和端口号（端口号由操作系统随机分配，每次都不一样）
print "Conneted to",s.getpeername() #获得连接机器的ip和端口号
结果如下：
Creating socket
Done!
Looking up port number...
80
Done
Connecting to remote host...
Done
Conneted from (‘122.207.52.35‘, 56207)
Conneted to (‘119.75.217.109‘, 80)
[Finished in 0.3s]
多次尝试ctrl+b，获得本机的端口号是连续的数字，并非随机分配。
（隔了一会再试会跳几个数，可能是有人也在搞这个吧。。。）
原文：http://my.oschina.net/u/2447940/blog/499126