def get_queryset(self):
    """
    Get the list of items for this view. This must be an interable, and may
    be a queryset (in which qs-specific behavior will be enabled).
    """
if self.queryset is not None:
    queryset = self.queryset
if hasattr(queryset, '_clone'):
    queryset = queryset._clone()
elif self.model is not None:
    queryset = self.model._default_manager.all()
else:
    pass
Django - queryset vs model in Generic View