title: How to use set() during iteration?
body: <p>How to use <code>set()</code> during iteration? I still have single value.</p>
  
  <pre><code>data = {'mynumber': set()}
  
  example = Example.objects.filter(user=request.user)
  for e in example:
      data['mynumber'].add(e.mynumber)
      print data #{'mynumber': set([15.0])}
  </code></pre>