Django Mini Project: Connecting Project and App URLs (With Initial Code + CS50W Reference)

In this tutorial, we build the foundation of a simple TODO List app in Django and understand how the project’s urls.py connects with the app’s urls.py.

This concept is also taught in Harvard’s CS50 Web Programming course (CS50W).

👉 Official CS50W URL:
https://cs50.harvard.edu/web/

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✅ Initial Context: What Are We Building?

We are creating a small Django app called tasks that will display a TODO list.

Before starting, we already have:

✔️ A Django project created
✔️ Django installed
✔️ Virtual environment activated
✔️ Development server running

This setup follows the same structure taught in CS50W’s Django section.

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❓ Q1. How do we create the tasks app?

Answer:

Run:

python manage.py startapp tasks

This creates:

tasks/

With:

admin.py
apps.py
models.py
views.py
migrations/

This is the standard app structure used in CS50W projects.

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❓ Q2. Why must we add tasks to INSTALLED_APPS?

Answer:

Open:

settings.py

Add:

'tasks',

Example:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',

    'tasks',
]

This step is required in every Django app, including in CS50W exercises.

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❓ Q3. What is the initial project-level urls.py file?

Answer:

Edit:

project/urls.py

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('tasks/', include("tasks.urls")),
]

This file works as the main URL controller.

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❓ Q4. Why do we use include("tasks.urls")?

Answer:

include() connects the project to the app.

It means:

“Send all URLs starting with tasks/ to the tasks app.”

This same method is used in CS50W’s hello, wiki, and commerce projects.

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❓ Q5. How do we create the app-level urls.py file?

Answer:

Create:

tasks/urls.py

Add:

from django.urls import path
from . import views

urlpatterns = [
    path("", views.index, name="index"),
]

This file maps app URLs to views.

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❓ Q6. What is the initial views.py file?

Answer:

Edit:

tasks/views.py

from django.http import HttpResponse

def index(request):
    return HttpResponse("Welcome to My TODO App")

This is your first Django view.

CS50W introduces views in exactly this way.

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❓ Q7. How are the two urls.py files connected?

Answer:

They are linked using include().

Project File:

path('tasks/', include("tasks.urls"))

App File:

path("", views.index)

This creates a routing chain.

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❓ Q8. What happens when I visit /tasks/?

Answer:

Request flow:

1️⃣ Browser → /tasks/
2️⃣ Project urls.py matches tasks/
3️⃣ Loads tasks/urls.py
4️⃣ Matches ""
5️⃣ Calls index()
6️⃣ Returns response

Result:

Welcome to My TODO App

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❓ Q9. Why is "" used in path("")?

Answer:

It means:

“No URL part remains.”

After removing tasks/, nothing is left.

So:

/tasks/ → ""

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❓ Q10. What is the complete initial project structure?

Answer:

myproject/
 ├── manage.py
 ├── myproject/
 │    ├── settings.py
 │    ├── urls.py
 │    └── wsgi.py
 └── tasks/
      ├── urls.py
      ├── views.py
      ├── models.py
      └── migrations/

This structure matches what CS50W teaches.

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❓ Q11. What if I add more pages later?

Answer:

Extend tasks/urls.py:

urlpatterns = [
    path("", views.index),
    path("add/", views.add),
    path("delete/", views.delete),
]

Now:

URL	View
/tasks/	index
/tasks/add/	add
/tasks/delete/	delete

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❓ Q12. Why is this system important in real projects?

Answer:

It provides:

✅ Clean organization
✅ App separation
✅ Easy debugging
✅ Reusability
✅ Professional structure

All major Django projects (including CS50W final projects) use this design.

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❓ Q13. How does this relate to CS50W?

Answer:

This routing system is taught in:

📘 CS50’s Web Programming with Python and JavaScript

Official Course Page:
👉 https://cs50.harvard.edu/web/

In CS50W, you learn this concept through:

• hello project
• wiki project
• commerce project
• Final project

Your TODO app follows the same professional pattern.

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📌 Final Summary (For Readers)

Django uses two urls.py files.
The project file routes to apps using include().
The app file routes to views.
This system is taught in CS50W and used in real-world Django projects.

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