title: Django REST Framework viewset per-action permissions
body: <p>Is there a best practice to assign a different permission to each action of a given <code>APIView</code> or <code>ViewSet</code>?</p>
  <p>Let's suppose I defined some permissions classes such as 'IsAdmin', 'IsRole1', 'IsRole2', ..., and I want to grant different permissions to the single actions (e.g. a user with Role1 can create or retrieve, a user with Role2 can update, and only an Admin can delete).</p>
  <p>How can I structure a class based view in order to assign a permission class to the 'create', 'list', 'retrieve', 'update', 'delete' actions?
  I'm trying to do so to have a class that can be reused for different tables that have the same permission pattern.</p>