title: Celery periodic task workflow
body: <p>I want to have a periodic celery task to do the following:</p>
  <ol>
  <li>Get the list of <code>receipt</code> items not yet scraped from the data base</li>
  <li>Call a task to scrap a specific website for every item on the previous list. Each task will return a list of products</li>
  <li>Save the products on the data base and update the <code>receipts</code> so it won't be used on the next call of the periodic task</li>
  </ol>
  <p>I think I could accomplish that by using chain, chunks and group, but I don't know how to do it. My idea was to chain the list from item 1 as input to item 2, but I would like every item on the list to be a separate task. It seems that &quot;chunks&quot; is a good candidate, but how can I pipe the list from item 1 to it? And how can I use the length of this list to define the number of tasks? Is it possible?</p>
  <p>Than the returned values of each one of those tasks would be pipe to a &quot;group&quot; composed of the tasks to save the products to the db and update the receipts.</p>