python scrapy简单模拟登录的代码分析

# -*- coding: utf-8 -*-
import scrapy
import re
 
class GithubLoginSpider(scrapy.Spider):
 name = 'github_login'
 allowed_domains = ['github.com']
 start_urls = ['https://github.com/login']
 
 def parse(self, response): # 发送Post请求获取Cookies
  authenticity_token = response.xpath('//input[@name="authenticity_token"]/@value').extract_first()
  utf8 = response.xpath('//input[@name="utf8"]/@value').extract_first()
  commit = response.xpath('//input[@name="commit"]/@value').extract_first()
  form_data = {
'login': 'pengjunlee@163.com',
'password': '123456',
'webauthn-support': 'supported',
'authenticity_token': authenticity_token,
'utf8': utf8,
'commit': commit}
  yield scrapy.FormRequest("https://github.com/session", formdata=form_data, callback=self.after_login)
 
 def after_login(self, response): # 验证是否请求成功
  print(re.findall('Learn Git and GitHub without any code!', response.body.decode()))

# -*- coding: utf-8 -*-
import scrapy
from scrapy import FormRequest,Request

class ExampleLoginSpider(scrapy.Spider):
 name = "login_"
 allowed_domains = ["example.webscraping.com"]
 start_urls = ['http://example.webscraping.com/user/profile']
 login_url = 'http://example.webscraping.com/places/default/user/login'
 def parse(self, response):
  print(response.text)
 def start_requests(self):
  yield scrapy.Request(self.login_url,callback=self.login)
 def login(self,response):
  formdata = {
'email':'liushuo@webscraping.com','password':'12345678'}
  yield FormRequest.from_response(response,formdata=formdata,
callback=self.parse_login)
 def parse_login(self,response):
  # print('>>>>>>>>'+response.text)
  if 'Welcome Liu' in response.text:
yield from super().start_requests()