title: Filtering the filters in Django Admin
body: <p>Here is my code for a school project
  <a href="http://dpaste.com/434311/" rel="nofollow">http://dpaste.com/434311/</a></p>
  
  <p>The code works fine, on studentadmin list page, I get filter for classes 
  which is good but as you can see my project is multi-tenant so in filter 
  area I want to show only the classes for the school the current user is 
  logged in (tracked thru sessions) but right now I can see list of all 
  classes from all schools</p>
  
  <p>so I want to replace this line</p>
  
  <pre><code>list_filter   = ['xclass']  
  </code></pre>
  
  <p>with something like</p>
  
  <pre><code>list_filter   = Class.objects.filter(school=request.session['school_id'])
  </code></pre>
  
  <p>how can I do it ?</p>