# get related tags from `tag_counter` and `theme_counter`
related_counts = {}
tags_pks = [tag.pk for tag in tags]
- for book in objects.iterator():
+ for book in objects:
for tag_pk, value in itertools.chain(book.tag_counter.iteritems(), book.theme_counter.iteritems()):
if tag_pk in tags_pks:
continue