python爬虫-urllib+cookie+json+POST

原文链接: python爬虫-urllib+cookie+json+POST

import urllib.request
from http.cookiejar import CookieJar

import json

url = 'http://www.baidu.com'
req_dict = {'k': 'v'}

cj = CookieJar()
handler = urllib.request.HTTPCookieProcessor(cj)
opener = urllib.request.build_opener(handler)

req_json = json.dumps(req_dict)
req_post = req_json.encode('utf-8')
headers = {}
#headers['Content-Type'] = 'application/json'
req = urllib.request.Request(url=url, data=req_post, headers=headers)

#urllib.request.install_opener(opener)
#res = urllib.request.urlopen(req)
# 或
res = opener.open(req)

res = res.read().decode('utf-8')
print(res)

发送json, 去掉

headers['Content-Type'] = 'application/json'

注释即可

相关知识:

默认的urllib.request.urlopen()不带cookie信息

urlopen是一个封装好的OpenerDirector实例，参数为(url, data, timeout)

通过build_opener可以创建OpenerDirector实例, build_opener(*handlers), 将handler类实例化增加到OpenerDirector中

使用urllib2.install_opener()会设置urllib2的全局opener, 也可以直接调用opener.open()代替全局的urlopen方法

如果已知cookie内容, 且固定不变, 可以在header中直接添加cookie内容发送请求

headers["Cookie"] = "xxxxx"
req = urllib.request.Request(url=url, headers=headers, data=req_post)

python3与python2.7部分区别:

python 3.x中urllib库和urilib2库合并为urllib库

urllib2.urlopen变为urllib.request.urlopen

urllib2.Request变为urllib.request.Request

urllib2.urlencode()变为urllib.parse.urlencode

cookielib变为http.cookiejar