from django.core.cache import caches
from django.db.models.signals import post_save, pre_delete, post_delete
import django.dispatch
-from catalogue.models import Tag, BookMedia, Book, Fragment, Collection
-from catalogue import tasks
+from catalogue.models import BookMedia, Book, Collection
from catalogue.utils import delete_from_cache_by_language
-from newtagging.models import tags_updated
permanent_cache = caches['permanent']