get_admin_url() for any model instance

models.py

from django.core import urlresolvers
from django.contrib.contenttypes.models import ContentType
from django.db import models

class MyModel(models.Model):

    def get_admin_url(self):
        content_type = ContentType.objects.get_for_model(self.__class__)
        return urlresolvers.reverse("admin:%s_%s_change" % (content_type.app_label, content_type.model), args=(self.id,))

source: http://stackoverflow.com/questions/10420271/django-how-to-get-admin-url-from-model-instance