Django / Flask Patterns

When to use this skill

• Maintaining Django or Flask applications.

• Writing migrations.

• Working with templates (Jinja2/DTL).

1. Django

• Models: Fat models, thin views. Put business logic in Model methods or Managers.

• CBV vs FBV: Context dependent, but stick to one style per project. Function-Based Views often cleaner for simple logic.

• ORM: Use select_related (FK) and prefetch_related (M2M) to avoid N+1 queries.

2. Flask

• Blueprints: Always use Blueprints to organize routes.

• Application Factory: Use the create_app() pattern for better testing and config management.

• Extensions: Initialize extensions (db.init_app(app) ) inside the factory.