def items(self, tag):
books = Book.tagged.with_any([tag])
- l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in books])
+ l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in books.iterator()])
descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags)]
if descendants_keys:
books = books.exclude(pk__in=descendants_keys)