urllib2下载网页的三种方法

# coding=UTF-8
import urllib2
import cookielib

url="http://www.baidu.com"


print '第一种方法'
response1 = urllib2.urlopen(url)
print response1.getcode();
print len(response1.read())


print '第二种方法'
request = urllib2.Request(url);
request.add_header("user-agent", "Mozilla/5.0")
response2 = urllib2.urlopen(request);
print response2.getcode();
print len(response2.read())


print '第三种方法'
cj = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
urllib2.install_opener(opener)
response3 = urllib2.urlopen(request);
print response3.getcode();
print cj
print response3.read()