Python Django

Full standards in python-django.md. Always-on summary:

Project structure:

• Split settings into settings/base.py, settings/local.py, settings/production.py
• One app per domain concept — never put all models in a single models.py monolith
• Use apps/ subdirectory; register apps with dotted path apps.users.apps.UsersConfig

Models and ORM:

• Always define __str__, class Meta with ordering, and explicit related_name on FK/M2M
• Use select_related('user', 'product') for FK traversal, prefetch_related for reverse/M2M — never N+1
• Wrap multi-step writes in transaction.atomic(); use select_for_update() for locking

DRF serializers:

• Use ModelSerializer with explicit fields = [...] — never use the magic all-fields shorthand
• Validate in validate_<field> or validate(); raise serializers.ValidationError
• Use SerializerMethodField for computed read-only fields

Views/URLs:

• Prefer APIView or ViewSet + DefaultRouter for REST endpoints
• Use permission_classes and authentication_classes explicitly per view
• Keep URL patterns in urls.py per app; include() them from the root urls.py

Migrations:

• Never edit migration files by hand; use makemigrations --name <descriptive-name>
• Add db_index=True via the model field, not raw SQL migrations
• Provide reverse functions in RunPython migrations or mark atomic=False carefully

Never:

• Never use print() — use logging.getLogger(__name__)
• Never put secrets in settings/base.py — use environ or django-environ
• Never use broad exception catches — always catch the specific exception type or re-raise

Related skills: error-handling, logging-standards, database-sql, api-conventions

Source: manikumarkv/devrunway-claude-plugin — distributed by TomeVault.