def add_photo_to_categorie(modeladmin, request, queryset): count = 0 for photo in queryset: if not Photo.objects.filter(image=photo,categorie=categorie).exists(): Photo(image=photo,categorie=categorie).save() count +=1 if count==1: message_bit = "1 photo was" else: message_bit = "{} photos were".format(count) modeladmin.message_user( request, "{} added to Categorie {}".format(message_bit,categorie) )