Django
Performance
use-count-method
use-count-method
Looks like you need to determine the number of records. Django provides the count() method which is more efficient than .len(). See https://docs.djangoproject.com/en/3.0/ref/models/querysets/
use-earliest-or-latest
use-earliest-or-latest
Looks like you are only accessing first element of an ordered QuerySet. Use latest() or earliest() instead. See https://docs.djangoproject.com/en/3.0/ref/models/querysets/#django.db.models.query.QuerySet.latest
access-foreign-keys
access-foreign-keys
You should use ITEM.user_id rather than ITEM.user.id to prevent running an extra query.