title: Why doesn't the CrawlSpider collect links?
body: <p>I am trying to run my first CrawlSpider, but the program terminates without any errors, while it does not return anything, it terminates with zero result. What's wrong with my code?</p>
  <pre><code>from scrapy.spiders import CrawlSpider, Rule
  from scrapy.linkextractors import LinkExtractor
  
  class FagorelectrodomesticoSpider(CrawlSpider):
      name = 'fagorelectrodomestico.com'
      allowed_domains = ['fagorelectrodomestico.com']
      start_urls = ['https://fagorelectrodomestico.com']
  
  rules = (
      Rule(LinkExtractor(allow='product/'), callback='parse_item', follow=True),
  )
  
  def parse_item(self, response):
      for doc in response.css('a.file'):
          doclink = doc.css('::attr(&quot;href&quot;)').get()
          product = Product()
          product['model'] = response.css('h2.data__symbol::text').get()
          product['brand'] = 'Fagor'
          product['file_urls'] = [doclink]
          yield product
  </code></pre>