title: Django GROUP BY field value
body: <p>Surprising that I could not find a way to make a group by query.</p>
  
  <p>I have a query set <code>qs</code> and I am trying to group by <code>some_prop.val</code>, considering <code>qs</code> is excluding entries where <code>some_prop</code> is <code>None</code>.</p>
  
  <p>Let's say the values are <code>[1, 2, 3]</code>, then I would be after a result like this:</p>
  
  <pre><code>{1: entries1, 2: entries2, 3: entries3}
  </code></pre>
  
  <p>Does the Django ORM provide any feature to group results like this?</p>