title: How to get the difference of two querysets in Django?
body: <p>I have to querysets. alllists and subscriptionlists</p>
  
  <pre><code>alllists = List.objects.filter(datamode = 'A')
  subscriptionlists = Membership.objects.filter(member__id=memberid, datamode='A')
  </code></pre>
  
  <p>I need a queryset called unsubscriptionlist, which possess all records in alllists except the records in subscription lists. How to achieve this?</p>