Python Spider crawls today's headlines for street photography

"""
Grab today's headlines and street photography
"""

import os
import time
import requests

from hashlib import md5


class SpiderToutiao(object):

    def  __init__ (self):
         #Specify the download directory 
        self.download_dir = os.path.join(os.path.dirname(os.path.abspath( __file__ )), " download " )
         #By analyzing the request, we found what we needed The address is as follows, and the pagination is controlled by offset + 20 
        self.url = " https://www.toutiao.com/search_content/ " \
                    " ?offset={0}&format=json&keyword=%E8%A1%97%E6 %8B%8D&autoload=true&count=20&cur_tab=3&from=gallery " 
        #Construct request header, disguised as Ajax request 
        self.headers = {
             " User-Agent " :"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) "
                          "Chrome/66.0.3359.139 Safari/537.36",
            "Referer": "https://www.toutiao.com/search/?keyword=%E8%A1%97%E6%8B%8D",
            "X-Requested-With": "XMLHttpRequest"
        }

    def handler(self, offset=0):

        while True:
            response = requests.get(self.url.format(offset), headers=self.headers)
            if response.status_code == 200:
                print("INFO -> Current URL: <%s>" % response.url)
                json_data = response.json().get( " data " )
                 #Start parsing data 
                if json_data:
                     for item in json_data:
                        _title = item.get("title")
                        _imgDict = item.get( " image_list " )
                         # Fix the URL, the default image address is a small image, we want a high-definition large image 
                        _imgList = [str( " http: " + _.get( " url " )).replace ( " list " , " large " ) for _ in _imgDict]

                        #Create storage directory 
                        _downloadDir = os.path.join(self.download_dir, _title)
                         if  not os.path.exists(_downloadDir):
                            os.makedirs(_downloadDir)

                        #Download and save the file 
                        for img in _imgList:
                            r = requests.get(img)
                            _file = os.path.join(_downloadDir, md5(r.content).hexdigest() + ".jpg")
                            if not os.path.exists(_file):
                                with open(_file, "wb") as f:
                                    f.write(r.content)
                            else :
                                 print ( " INFO -> ig <%s> " % _file)
                 # indicates that there is no data, the program exits 
                else :
                     break

                #Pagination auto increment
                offset += 20
                #Interval time 
                time.sleep(.9 )
             else :
                 print (response.reason)
                exit(999)


if __name__ == "__main__":

    spider = SpiderToutiao()
    spider.handler()