text: import requests
  from lxml import html
  import redis
  
  client = redis.StrictRedis()
  source = requests.get('http://dongyeguiwu.zuopinj.com/5525').content
  selector = html.fromstring(source)
  
  url_list = selector.xpath('//div[@class="book_list"]/ul/li/a/@href')
  for url in url_list:
      client.lpush('url_queue', url)