Django Development Guidelines

General

• Follow the Django Style Guide and PEP 8.
• Use Django's built-in features whenever possible (authentication, admin, forms).
• Keep applications modular and reusable.

Models (models.py)

• Use descriptive model and field names.
• Define __str__ methods for all models.
• Add Meta options for ordering, verbose names, etc.
• Use ForeignKey with on_delete specified appropriately (e.g., models.CASCADE, models.SET_NULL).
• Example: author = models.ForeignKey(User, on_delete=models.CASCADE, related_name='posts')

Views (views.py)

• Prefer Class-Based Views (CBVs) for common patterns (List, Detail, Create, Update, Delete).
• Use Function-Based Views (FBVs) for simple or highly custom logic.
• Implement proper authentication and permissions (@login_required, PermissionRequiredMixin).
• Handle exceptions gracefully (e.g., try...except ObjectDoesNotExist).
• Use get_object_or_404 shortcut.

Templates

• Organize templates in app-specific directories (templates/<app_name>/).
• Use template inheritance ({% extends 'base.html' %}).
• Load static files using {% load static %} and {% static 'path/to/file.css' %}.
• Avoid complex logic in templates; use template tags or filters instead.

ORM

• Use queryset filtering (.filter(), .exclude()) efficiently. Avoid loading unnecessary data.
• Utilize select_related (for one-to-one/foreign key) and prefetch_related (for many-to-many/reverse foreign key) to optimize database queries.
• Use .annotate() for database-level aggregations.
• Be mindful of lazy loading and potential N+1 query problems.

Forms (forms.py)

• Use Django Forms for data validation and HTML generation.
• Prefer ModelForm for forms tied directly to models.
• Define custom validation methods (clean_<fieldname>(), clean()).

URLs (urls.py)

• Use descriptive URL names (path('articles/<int:pk>/', views.ArticleDetailView.as_view(), name='article-detail')).
• Include app-specific urls.py files using include().

Settings (settings.py)

• Use environment variables for sensitive data (SECRET_KEY, database credentials). Do not commit secrets.
• Configure STATIC_URL, STATIC_ROOT, MEDIA_URL, MEDIA_ROOT correctly.

Testing

• Write unit tests and integration tests using Django's TestCase or pytest-django.
• Test models, views, forms, and utilities.