title: Django - Build a model filter from string
body: <p>Is it possible to filter models using string arguments?</p>
  
  <p>Consider the following filter: </p>
  
  <pre><code>some_model.filter(parameter__gte = x)
  </code></pre>
  
  <p>I want to build that filter argument using strings.</p>
  
  <p>eg. </p>
  
  <pre><code>if equality == "&gt;" and argument == x: query = "{0}__gte".format(parameter)
  </code></pre>
  
  <p>Then filter using that built argument.</p>
  
  <pre><code>some_model.filter(query = x)
  </code></pre>
  
  <p>Is something along those lines possible without using raw sql?</p>