django

## When to use this skill

Use this skill whenever the user wants to:
- Create Django web applications with models, views, and templates
- Configure projects, apps, migrations, and deployment
- Build REST APIs with Django REST Framework
- Set up Django admin, forms, and authentication

## How to use this skill

### Workflow

1. **Create project** — scaffold with `django-admin startproject`
2. **Add apps** — create feature apps with `python manage.py startapp`
3. **Define models** — write models, create and run migrations
4. **Build views and URLs** — implement views, wire URL patterns
5. **Test and deploy** — run tests, configure production settings

### Quick Start Example

```python
# models.py
from django.db import models

class Article(models.Model):
    title = models.CharField(max_length=200)
    body = models.TextField()
    published_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ['-published_at']

    def __str__(self):
        return self.title

# views.py
from django.shortcuts import render, get_object_or_404
from .models import Article

def article_list(request):
    articles = Article.objects.all()
    return render(request, 'articles/list.html', {'articles': articles})

def article_detail(request, pk):
    article = get_object_or_404(Article, pk=pk)
    return render(request, 'articles/detail.html', {'article': article})

# urls.py
from django.urls import path
from . import views

urlpatterns = [
    path('articles/', views.article_list, name='article-list'),
    path('articles/<int:pk>/', views.article_detail, name='article-detail'),
]
```

```bash
# Setup workflow
django-admin startproject myproject
python manage.py startapp articles
python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver
```

### Django REST Framework Example

```python
# serializers.py
from rest_framework import serializers
from .models import Article

class ArticleSerializer(serializers.ModelSerializer):
    class Meta:
        model = Article
        fields = ['id', 'title', 'body', 'published_at']

# views.py
from rest_framework import viewsets
from .models import Article
from .serializers import ArticleSerializer

class ArticleViewSet(viewsets.ModelViewSet):
    queryset = Article.objects.all()
    serializer_class = ArticleSerializer
```

## Best Practices

- One app per responsibility; normalize models and add database indexes
- Keep views thin — place business logic in services or model methods
- Always enable CSRF protection and configure security middleware
- Use `select_related` and `prefetch_related` to avoid N+1 queries
- Run tests with `python manage.py test`; use `--parallel` for speed

## Reference

- Official documentation: https://docs.djangoproject.com/

## Keywords

django, ORM, MTV, migrations, Python web, REST framework, admin, views, templates