python 爬取网页的最基础三种方法

# coding:utf8import cookielibimport urllib2url = "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(url)print response3.getcode()print cjprint len(response3.read())

待续。。。。