Scrapy基础(十四)————Scrapy实现知乎模拟登陆

  模拟登陆大体思路见此博文，本篇文章只是将登陆在scrapy中实现而已

之前介绍过通过requests的session 会话模拟登陆；必须是session,涉及到验证码和xsrf的
写入cookie验证的问题；在scrapy中不需担心此问题，因为Request会保证这是一个会话，并且自动传递cookies
原理想通，因为验证码识别的问题，这里先使用cookie模拟登陆

# -*- coding: utf-8 -*- 

import scrapy
import json
import re





class ZhihuSpider(scrapy.Spider):

    name = "zhihu"
    allowed_domains = ["zhihu.com"]
    start_urls = ['http://www.zhihu.com/']
    #头部
    headers = {
    "User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36",
    "Host":"www.zhihu.com",
    "Referer":"https://www.zhihu.com/",
}
    #从已经登陆的浏览在中copy下来的
    cookies = {
    "d_c0":"",
    "l_cap_id":"",
    "r_cap_id":"",
    "cap_id":"",
    "_zap":"",
    "__utmc":"",
    "__utmb":"",
    "__utmv":"",
    "__utma":"",
    "__utmz":"5",
    "q_c1":"",
    }
    #最开始请求的reqeust函数，自动调用,将首次获取的response返回给登陆函数（里面有xsrf）
    def start_requests(self):
        #必须带上cookie；return返回，不用生成器，只需爬取登陆页面一次，而且必须返回一个可迭代对象,所以是列表
        return [scrapy.Request(url="https://www.zhihu.com/#signin",cookies=self.cookies,headers=self.headers,callback=self.login)]


    #知乎登录
    def login(self,response):
        #正则匹配出xsrf
        response_text = response.text
        match_obj = re.match('.*name="_xsrf" value="(.*?)"', response_text, re.DOTALL)
        if match_obj:
            xsrf = (match_obj.group(1))

        url = "https://www.zhihu.com/login/phone_num"
        data={
            "_xsrf":xsrf,
            'remember_me': 'true',
            "password":"",
            "phone_num":""
        }

        #将获取到的xsrf加载到cookie中
        self.cookies["_xsrf"] = xsrf
        #通过FormRequest提交表单,这里的request对象和之前的session一样,还是处于刚刚的对话中；回调给检查登陆的函数
        return [scrapy.FormRequest(url=url,headers=self.headers,formdata=data,callback=self.check_login)]

    #查看登录状态；登陆成功则默认回调parse函数进行解析网页
    def check_login(self,response):
        text_json = json.load(response.text)
        if "msg" in text_json and text_json["msg"]=="\u767b\u5f55\u6210\u529f":
            for urls in self.start_urls:
               yield scrapy.Request(url=urls,dont_filter=True,headers=self.headers)




    def parse(self, response):
        pass