django-patterns

Django Patterns Skill

Idiomatic Django for production systems. Covers models, views, ORM patterns, and project layout.

When to Activate

Activate when:

• Writing new Django apps or services
• Reviewing Django code for correctness and idiom
• Designing model relationships and ORM queries
• Building views with class-based views or function-based views
• Configuring URL routing and middleware

Project Structure

Standard Layout

manage.py
mysite/
    __init__.py
    settings.py
    urls.py
    wsgi.py
myapp/
    __init__.py
    models.py
    views.py
    urls.py
    admin.py
    apps.py

Decoupled Layout (Recommended)

manage.py
myapp/
    __init__.py
    models.py
    views.py
    urls.py
mysite/
    __init__.py
    settings.py
    urls.py
    wsgi.py

Import apps as top-level modules without project prefix.

Models and ORM

Basic Model Definition

from django.db import models

class Reporter(models.Model):
    full_name = models.CharField(max_length=70)

    def __str__(self):
        return self.full_name

class Article(models.Model):
    pub_date = models.DateField()
    headline = models.CharField(max_length=200)
    content = models.TextField()
    reporter = models.ForeignKey(Reporter, on_delete=models.CASCADE)

    def __str__(self):
        return self.headline

Field Types and Options

class Book(models.Model):
    class Status(models.TextChoices):
        DRAFT = 'draft', 'Draft'
        PUBLISHED = 'published', 'Published'
        ARCHIVED = 'archived', 'Archived'

    title = models.CharField(max_length=200)
    author = models.ForeignKey(Author, on_delete=models.CASCADE, related_name='books')
    isbn = models.CharField(max_length=13, unique=True)
    published_date = models.DateField()
    price = models.DecimalField(max_digits=10, decimal_places=2)
    status = models.CharField(max_length=10, choices=Status.choices, default=Status.DRAFT)
    tags = models.ManyToManyField('Tag', blank=True)

    class Meta:
        ordering = ['title']
        indexes = [
            models.Index(fields=['title', 'author']),
            models.Index(fields=['published_date']),
        ]