Django QuerySetManager: Add new QuerySet methods using a Model inner class

querysetmanager.py

# Django Query Set Manager
#
# https://gist.github.com/1026248


from django.db import models


class QuerySetManager(models.Manager):
    """
    Enables adding new QuerySet methods using a Model inner class.

    http://djangosnippets.org/snippets/734/
    https://code.djangoproject.com/ticket/15062
    """

    def get_query_set(self):
        return self.model.QuerySet(self.model)

    def __getattr__(self, attr, *args):
        if attr.startswith('_'):
            raise AttributeError
        return getattr(self.get_query_set(), attr, *args)