python 2.7 检测一个网页是否能正常访问的方法

#!/bin/env python
#coding:utf-8


import requests
import sys


url = "https://mp.csdn.net/"
r = requests.get(url, timeout=5)
code = r.status_code


if code == 200: 
	print "OK 网站访问正常"
	sys.exit(0)
else:
	print "Error 不能访问！"
	sys.exit(2)