import urllib.request   #python3中将urllib2拆分为了urllib.request、urllib.error、urllib.response等

import http.cookiejar

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

print("第一种方法")

response1 = urllib.request.urlopen(url)

print(response1.getcode())  #打印response1的状态码看是否请求成功, 200表示请求成功

print(len(response1.read())) #打印返回网页内容长度

print("第二种方法")

request = urllib.request.Request(url)

request.add_header("user-agent", "Mozilla/5.0") #模拟浏览器访问

request2 = urllib.request.urlopen(request)

print(request2.getcode())

print(len(request2.read()))

print("第三种方法")

cj = http.cookiejar.CookieJar()

opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj)) #在请求对象中添加cookie

urllib.request.install_opener(opener)

request3 = urllib.request.urlopen(url)

print(request3.getcode())

print(len(request3.read()))