text: from abc import abstractmethod
  
  from kingfisher_scrapy.base_spiders import PeriodicSpider
  from kingfisher_scrapy.util import components
  
  
  class UruguayBase(PeriodicSpider):
      download_delay = 1
  
      # BaseSpider
      date_format = 'year-month'
      default_from_date = '2017-11'
  
      # PeriodicSpider
      pattern = 'http://comprasestatales.gub.uy/ocds/rss/{0.year:d}/{0.month:02d}'
      formatter = staticmethod(components(-2))
      start_requests_callback = 'parse_list'
  
      @abstractmethod
      def parse_list(self, response):
          pass
  