title: Combine __in and contains query filter to make a more complex filter in django
body: <p>So here's my question :<br>
  Say i have a list of some people's full names and I want to filter my users to check which one of those people are already of my users.</p>
  
  <p>The problem is that users have first name and last name but what I have is the list  of full names, meaning 'first_name+last_name'.  </p>
  
  <p>I was trying to filter in 3 steps, first filter all users whose first_names where in the list and then filter with their last_name.The third step would be to check for exact matches between the results, But the problem is I can't filter my users with their first_name in the list because <code>__in</code> operator looks for exact matches not partial matches.<br>
  <strong>So</strong>:<br>
  Is there anyway to do a filter like this :  </p>
  
  <pre><code>users.filter(first_name__in__icontains=list_of_people)   
  </code></pre>
  
  <p>or even better, can i have a filter like :   </p>
  
  <pre><code>users.filter((first_name+ ' ' + last_name)__in=list_of_people)
  </code></pre>
  
  <p>?<br>
  Any help would be appreciated :)<br>
   Thanks</p>