urlib2下载网页的三种方法

第一种：

# coding：utf8
import  urlib2
url="http://www.baidu.com"
response1=urlib2.urlopen(url)
print response1.getcode()
print len(response1.read())

第二种：

request=urlib2.Request(url)
request.add_header("user-agent","Mozilla/5.0")

response2=urlib2.urlopen(request)
print response.getcpde()
print len(response2.read())

第三种：

cj=cookielib.CookieJar()

opener=urlib2.build_opener(urlib2.HTTPCookieProcessor(cj))

urlib2.install_opener(opener)

response3=urlib2.urlopen(url)

print response3.getcode()

print cj

print response3.read()