title: Django guests vote only once poll
body: <p>I'm new to Django but am working on the tutorial on the Django website for creating a poll.</p>
  
  <p>What is the best way to make it so guests (no registration / login) can only vote once on a poll?</p>
  
  <ul>
  <li>IP (Don't want IP because people sharing a network can only vote once).</li>
  <li>Cookie (User can delete the cookie but seems like the best approach).</li>
  <li>Session (If the user closes the browser the session will change).</li>
  </ul>
  
  <p>I'm guessing that Cookie would be the best approach but is there a better way for Django?</p>