title: Django Query __isnull=True or = None
body: <p>this is a simple question. I'd like to know if it is the same to write:</p>
  
  <pre><code>queryset = Model.objects.filter(field=None)
  </code></pre>
  
  <p>than:</p>
  
  <pre><code>queryset = Model.objects.filter(field__isnull=True)
  </code></pre>
  
  <p>I'm using django 1.8</p>