title: Django Queryset to dict for use in json
body: <p>I have the following queryset:</p>
  
  <pre><code>prices = Price.objects.filter(product=product).values_list('price', 'valid_from')
  </code></pre>
  
  <p>How can i get the prices as "json"</p>
  
  <pre><code>{"aaData": [
      ["70.1700", "2007-01-01"], # price, valid_form
      ["72.6500", "2008-01-01"], # price, valid_form
      ["74.5500", "2009-01-01"], # price, valid_form
      ["76.6500", "2010-01-01"]
  ]}
  </code></pre>