title: Transient use of Django Model instances
body: <p>I have a use case where a particular class can either be transient or persistent. Transient instances are build from a JSON payload on a PUT call, and may either be persisted to the database or used during the server call and then either returned or discarded. What is best practice for this case? My options seem to be:</p>
  
  <ul>
  <li>Write <em>two</em> classes, one of which is a models.Model subclass, and the other of which isn't, and make them implement the same API, or</li>
  <li>Use the Model subclass, but be careful not to call save().</li>
  </ul>
  
  <p>Is either of these preferable, according to conventional use of Django models?</p>