shelf_is_set = len(tags) == 1 and tags[0].category == 'set'
my_shelf_is_set = shelf_is_set and request.user.is_authenticated() and request.user == tags[0].user
shelf_is_set = len(tags) == 1 and tags[0].category == 'set'
my_shelf_is_set = shelf_is_set and request.user.is_authenticated() and request.user == tags[0].user