scrapy Formrequest用法（豆瓣登录案例）

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

class DbSpider(scrapy.Spider):
    name = 'db'
    allowed_domains = ['douban.com']
    start_urls = ['https://accounts.douban.com/login']
    login_url = 'https://accounts.douban.com/login'

    headers = {
        'Referer': 'https: // accounts.douban.com / passport / login',
        'User - Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.26 Safari/537.36 Core/1.63.6721.400 QQBrowser/10.2.2243.400'
    }
    def parse(self, response):
        formdata={
            'source':'index_nav',
            'form_email':'....',
            'form_password':'....'

        }
        yield scrapy.FormRequest(url=self.login_url,formdata=formdata,callback=self.login_after,headers=self.headers)

    def login_after(self,response):
        res = response.xpath('//a[@class="bn-more"]/span/text()').extract_first()
        if res is None:
            print('登陆失败！')
        else:
            print('登陆成功!{}'.format(res))