title: How do I dynamically determine if a Model class exist in Google App Engine?
body: <p>I want to be able to take a dynamically created string, say "Pigeon" and determine at runtime whether Google App Engine has a Model class defined in this project named "Pigeon". If "Pigeon" is the name of a existant model class, I would like to then get a reference to the Pigeon class so defined.</p>
  
  <p>Also, I don't want to use eval at all, since the dynamic string "Pigeon" in this case, comes from outside.</p>