REST APIs with Django REST Framework

Django REST Framework (DRF) is a powerful and flexible toolkit for building Web APIs with Django. It simplifies API development by providing serialization, authentication, permissions, and built-in views.

In this guide, we’ll cover:

Installing Django and DRF
Creating a Django project
Setting up a REST API with DRF
Implementing CRUD operations
Adding authentication

1. Installing Django and DRF

Ensure you have Python installed, then install Django and DRF:

pip install django djangorestframework

2. Creating a Django Project and App

Create a new Django project and an app for our API:

django-admin startproject myproject
cd myproject
django-admin startapp myapp

Add 'rest_framework' and 'myapp' to INSTALLED_APPS in settings.py:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',  # Django REST Framework
    'myapp',  # Our app
]

Run migrations:

python manage.py migrate

3. Setting Up a Django REST API

We’ll create an API for managing users with CRUD (Create, Read, Update, Delete) operations.

3.1 Defining the User Model

In myapp/models.py, define a User model:

from django.db import models

class User(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(unique=True)
    age = models.IntegerField()

    def __str__(self):
        return self.name

Apply migrations:

python manage.py makemigrations myapp
python manage.py migrate

4. Serializing the Model

DRF uses serializers to convert model instances to JSON.

Create myapp/serializers.py:

from rest_framework import serializers
from .models import User

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = '__all__'

5. Creating API Views

DRF supports multiple types of views. We’ll use Class-based API views.

Create myapp/views.py:

from rest_framework import generics
from .models import User
from .serializers import UserSerializer

class UserListCreateView(generics.ListCreateAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

class UserDetailView(generics.RetrieveUpdateDestroyAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

ListCreateAPIView allows GET (list all users) and POST (create a user).
RetrieveUpdateDestroyAPIView allows GET, PUT, PATCH, and DELETE on a specific user.

6. Defining URL Patterns

Create myapp/urls.py:

from django.urls import path
from .views import UserListCreateView, UserDetailView

urlpatterns = [
    path('users/', UserListCreateView.as_view(), name='user-list'),
    path('users/<int:pk>/', UserDetailView.as_view(), name='user-detail'),
]

Include the app URLs in myproject/urls.py:

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

urlpatterns = [
    path('admin/', admin.site.urls),
    path('api/', include('myapp.urls')),
]

Run the development server:

python manage.py runserver

Test the API at:

GET /api/users/ – List all users
POST /api/users/ – Create a user
GET /api/users/<id>/ – Retrieve a user
PUT /api/users/<id>/ – Update a user
DELETE /api/users/<id>/ – Delete a user

7. Adding Authentication

Modify settings.py to enable authentication:

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework.authentication.SessionAuthentication',
        'rest_framework.authentication.TokenAuthentication',
    ],
    'DEFAULT_PERMISSION_CLASSES': [
        'rest_framework.permissions.IsAuthenticated',
    ],
}

Install Token Authentication:

pip install djangorestframework-simplejwt

Add JWT authentication to settings.py:

REST_FRAMEWORK['DEFAULT_AUTHENTICATION_CLASSES'].append(
    'rest_framework_simplejwt.authentication.JWTAuthentication'
)

Run migrations:

python manage.py migrate

Create a view for user authentication:

from rest_framework_simplejwt.views import TokenObtainPairView, TokenRefreshView
from django.urls import path

urlpatterns += [
    path('token/', TokenObtainPairView.as_view(), name='token_obtain_pair'),
    path('token/refresh/', TokenRefreshView.as_view(), name='token_refresh'),
]

Test authentication:

Get a token (POST /api/token/) with:

{
    "username": "admin",
    "password": "password"
}

Use the token in requests:
- Add Authorization: Bearer <token> in headers.

8. Browsable API

DRF provides a browsable API. Add this to INSTALLED_APPS:

'rest_framework.authtoken'

Run:

python manage.py createsuperuser