gistfile1.py

def GetAdminAddURL(self, model_class=None, model_instance=None):
    # Se passar a classe, utiliza a classe, se passar a instancia
    # pega a classe dela.
    if model_class is None:
        model_class = model_instance.__class__
    from django.core import urlresolvers
    from django.contrib.contenttypes.models import ContentType
    content_type = ContentType.objects.get_for_model(model_class)
    return urlresolvers.reverse("admin:%s_%s_add" % (content_type.app_label,
        content_type.model))