How I resolved the Python scrapy wechat 302 error

I tried to scrape weixin.sogou.com website. And I tried to scrape some data during some certain timeframe. They have a parameter tsn to control the searching time frame. If tsn=1, means you are searching within one day.

I wrote a python scrapy code to do this. Here is the code:

import scrapy

class QuotesSpider(scrapy.Spider):
   name="quotes"
   def start_requests(self):
      yield scrapy.FormRequest(url='http://weixin.sogou.com/weixin',
                           formdata={'type':'2',
                                     'ie':'utf8',
                                     'query':"the shape of water",
                                     'tsn':'1',
                                     'ft':'',
                                     'et':'',
                                     'interation':'',
                                     'wxid':'',
                                     'usip':''},
                            method='get',callback=self.parse)
   def parse(self, response):

        filename="quotes.html"
        with open(filename,"wb") as f:
                f.write(response.body)
        self.log("Saved file %s" % filename)

When I run the code, it is always redirected to homepage, wexin.sogou.com

Then I tried many methods. At last, someone suggested use http://weixin.sogou.com/weixin?type=2 as referrer on headers. I tried it. Works. Won't redirect anymore. 

import scrapy

import time

from bs4 import BeautifulSoup

class QuotesSpider(scrapy.Spider):

   name="quotes"

   headers = {

    'Cookie': Cookie,

    "User-Agent": UA,

    "Referer": "http://weixin.sogou.com/weixin?type=2"

    }

   def start_requests(self,filename=None):

                  yield scrapy.http.FormRequest(url='http://weixin.sogou.com/weixin',

                           formdata={'type':'2',

                                     'ie':'utf8',

                                     'query':query,

                                     'tsn':'1',

                                     'ft':'',

                                     'et':'',

                                    #  'sst0': str(int(time.time()*1000)),

                                    # 'page': str(1),

                                     'interation':'',

                                     'wxid':'',

                                     'usip':''},

                           headers=self.headers,method='get', dont_filter=True,

                          meta = {'dont_redirect': True, "handle_httpstatus_list" : [301, 302, 303]},

                           callback=self.parse)