def get_model_from_url_params(app_name, model_name):
 model = registry.get_by_natural_key(app_name, model_name)
 if (model is None):
  raise Http404
 return model

def get_model_from_url_params ( app_name , model_name ) : model = registry . get_by_natural_key ( app_name , model_name ) if ( model is None ) : raise Http404 return model
retrieve a content type from an app_name / model_name combo .