'''
urllib2下载网页的三种方法
'''
import urllib2,cookielib
url='http://www.baidu.com'
print u'第一种方法_直接请求'
response1=urllib2.urlopen(url)
print response1.getcode()
print len(response1.read())
print u'第二种方法_添加data、httpheader'
request=urllib2.Request(url)
request.add_header('user-agent','Mozilla/5.0')
response2=urllib2.urlopen(request)
print response2.getcode()
print len(response2.read())
print u'第三种方法_添加特殊场景处理器_以cookie为例'
cj=cookielib.CookieJar()
opener=urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
urllib2.install_opener(opener)
response3=urllib2.urlopen(url)
print response3.getcode()
print len(response3.read())