Project anatomy

Chapter 3 of Module 17 — Django for AI Web Apps.

Django splits your code into a project (the deployable site) and one or more apps (reusable feature modules). ChurnScope has one project (churnscope) and one app (scoring):

example-app/
├── manage.py              # the CLI: runserver, migrate, test, createsuperuser, …
├── churnscope/            # the PROJECT (site-wide config)
│   ├── settings.py        # installed apps, database, templates, security
│   ├── urls.py            # the root URL map
│   ├── wsgi.py / asgi.py  # the entry points a production server talks to
└── scoring/               # an APP (one feature: churn scoring)
    ├── models.py          # data → database tables (the ORM)
    ├── views.py           # request → response (calls the scorer)
    ├── urls.py            # this app's URL map
    ├── forms.py           # input validation
    ├── admin.py           # what shows up in /admin/
    ├── scorer.py          # the model stand-in (plain Python)
    ├── templates/         # HTML
    └── migrations/        # versioned schema changes

manage.py — your control panel

Every Django task goes through manage.py:

Command	What it does
python manage.py runserver	Start the dev server on :8000
python manage.py makemigrations	Turn model changes into migration files
python manage.py migrate	Apply migrations to the database
python manage.py createsuperuser	Make an admin login
python manage.py test	Run the test suite
python manage.py shell	A Python REPL with Django loaded

settings.py — the wiring

The important knobs (see churnscope/settings.py):

• INSTALLED_APPS — which apps are active (the admin, auth, sessions… and scoring).

• DATABASES — ChurnScope uses SQLite (a single file, zero setup) for the demo; swap in Postgres for production by changing this one dict.

• TEMPLATES — with APP_DIRS=True, Django finds scoring/templates/ automatically.

• DEBUG, SECRET_KEY, ALLOWED_HOSTS — the three settings you must change for production (see the deployment chapter).

The request cycle, end to end

When you submit the form:

1. The browser sends POST / to the dev server.

2. churnscope/urls.py includes scoring/urls.py, which maps "" → views.index.

3. views.index validates the form, calls the scorer, writes a row via the model (ORM), and renders the template with the result.

4. The filled-in HTML comes back as the response.

That’s MTV in motion. The next chapters open each box.