related_themes = book.related_themes()
for category in 'author', 'kind', 'genre', 'epoch':
- self.assertTrue('tag' in [tag.slug for tag in book.tags.filter(category=category)],
+ self.assertTrue('tag' in book.tags.filter(category=category).values_list('slug', flat=True),
'missing related tag for %s' % category)
self.assertTrue('tag' in [tag.slug for tag in related_themes])