Python-сообщество

class Subscribe(models.Model):
    user = models.ForeignKey(User, related_name = 'friend')
    who = models.ForeignKey(User, blank=True, related_name = 'forfriend')

user    who
----------------
user1  user2
user3  user2
user4  user3
user2  user3
user1  user3
user4  user2
user4  user3
user1 user4

user3   4
user2   3
user4   1

 User.objects.annotate(count=Count("forfriend")).filter(count__gt=0).order_by("-count")