def to_representation(self, value):
request = self.context['request']
if not hasattr(request, 'liked_books'):
- if request.user.is_authenticated():
+ if request.user.is_authenticated:
request.liked_books = set(Book.tagged.with_any(request.user.tag_set.all()).values_list('id', flat=True))
else:
request.liked_books = None