import urllib.request
import http.cookiejar

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

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

print ('第二种方法')
request=urllib.request.Request(url)
request.add_header("user-agent","Mozilla/5.0")#将爬虫伪装成浏览器
response2=urllib.request.urlopen(request)
print (response2.getcode())#打印状态码
print (len(response2.read()))#打印内容长度

print ('第三种方法')
cj = http.cookiejar.CookieJar()
opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
urllib.request.install_opener(opener)
response3=urllib.request.urlopen(url)
print (response1.getcode())
print (cj)  #输出cookie
print (response1.read())