FastAPI vs Django REST Framework: A Comprehensive Comparison
Table of Contents
Fundamental Concepts
FastAPI
FastAPI is built on top of Starlette for the web parts and Pydantic for the data parts. It leverages Python type hints to perform automatic data validation, serialization, and deserialization. FastAPI uses an asynchronous programming model, which allows it to handle a large number of concurrent requests efficiently. It also generates interactive API documentation automatically using OpenAPI and Swagger UI.
Django REST Framework
Django REST Framework is an extension of the Django web framework. It provides a set of tools and views to simplify the process of building RESTful APIs. DRF follows the Django philosophy of convention over configuration, providing a high - level of abstraction. It integrates well with Django’s ORM, authentication, and permission systems.
Usage Methods
Installation
FastAPI
To install FastAPI, you can use pip:
pip install fastapi uvicorn
Here, uvicorn is an ASGI server that can run FastAPI applications.
Django REST Framework
First, install Django:
pip install django
Then, install Django REST Framework:
pip install djangorestframework
Add rest_framework to your INSTALLED_APPS in your Django project’s settings.py file:
INSTALLED_APPS = [
#...
'rest_framework',
#...
]
Basic API Creation
FastAPI
from fastapi import FastAPI
app = FastAPI()
@app.get("/")
def read_root():
return {"Hello": "World"}
@app.get("/items/{item_id}")
def read_item(item_id: int, q: str = None):
return {"item_id": item_id, "q": q}
To run the FastAPI application, use the following command:
uvicorn main:app --reload
Django REST Framework
First, create a new Django project and an app:
django-admin startproject myproject
cd myproject
python manage.py startapp myapp
In myapp/models.py:
from django.db import models
class Item(models.Model):
name = models.CharField(max_length=100)
In myapp/serializers.py:
from rest_framework import serializers
from .models import Item
class ItemSerializer(serializers.ModelSerializer):
class Meta:
model = Item
fields = '__all__'
In myapp/views.py:
from rest_framework import viewsets
from .models import Item
from .serializers import ItemSerializer
class ItemViewSet(viewsets.ModelViewSet):
queryset = Item.objects.all()
serializer_class = ItemSerializer
In myproject/urls.py:
from django.contrib import admin
from django.urls import path, include
from rest_framework.routers import DefaultRouter
from myapp.views import ItemViewSet
router = DefaultRouter()
router.register(r'items', ItemViewSet)
urlpatterns = [
path('admin/', admin.site.urls),
path('', include(router.urls)),
]
Run the Django development server:
python manage.py makemigrations
python manage.py migrate
python manage.py runserver
Common Practices
Data Validation
FastAPI
FastAPI uses Pydantic for data validation. You can define data models using Pydantic classes:
from fastapi import FastAPI
from pydantic import BaseModel
app = FastAPI()
class Item(BaseModel):
name: str
price: float
is_offer: bool = None
@app.post("/items/")
def create_item(item: Item):
return item
FastAPI will automatically validate the incoming data against the Item model.
Django REST Framework
DRF uses serializers for data validation. In the previous example, the ItemSerializer class validates the data when creating or updating an Item object:
serializer = ItemSerializer(data={'name': 'New Item', 'price': 9.99})
if serializer.is_valid():
item = serializer.save()
else:
errors = serializer.errors
Authentication and Authorization
FastAPI
FastAPI can integrate with various authentication mechanisms. For example, using HTTP Basic Auth:
from fastapi import Depends, FastAPI, HTTPException
from fastapi.security import HTTPBasic, HTTPBasicCredentials
import secrets
app = FastAPI()
security = HTTPBasic()
def get_current_username(credentials: HTTPBasicCredentials = Depends(security)):
correct_username = secrets.compare_digest(credentials.username, "admin")
correct_password = secrets.compare_digest(credentials.password, "password")
if not (correct_username and correct_password):
raise HTTPException(
status_code=401,
detail="Incorrect email or password",
headers={"WWW-Authenticate": "Basic"},
)
return credentials.username
@app.get("/users/me")
def read_current_user(username: str = Depends(get_current_username)):
return {"username": username}
Django REST Framework
DRF has built - in support for various authentication and authorization classes. For example, to use Token Authentication:
First, add rest_framework.authtoken to your INSTALLED_APPS in settings.py:
INSTALLED_APPS = [
#...
'rest_framework.authtoken',
#...
]
Run python manage.py migrate to create the necessary database tables.
Then, in your settings.py, set the authentication classes:
REST_FRAMEWORK = {
'DEFAULT_AUTHENTICATION_CLASSES': [
'rest_framework.authentication.TokenAuthentication',
]
}
You can then use the IsAuthenticated permission class in your views:
from rest_framework.permissions import IsAuthenticated
from rest_framework.viewsets import ModelViewSet
from .models import Item
from .serializers import ItemSerializer
class ItemViewSet(ModelViewSet):
queryset = Item.objects.all()
serializer_class = ItemSerializer
permission_classes = [IsAuthenticated]
Database Integration
FastAPI
FastAPI itself does not have a built - in ORM. You can use external ORMs like SQLAlchemy. Here is a simple example of using SQLAlchemy with FastAPI:
from fastapi import FastAPI
from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
app = FastAPI()
SQLALCHEMY_DATABASE_URL = "sqlite:///./test.db"
engine = create_engine(SQLALCHEMY_DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()
class Item(Base):
__tablename__ = "items"
id = Column(Integer, primary_key=True, index=True)
name = Column(String)
Base.metadata.create_all(bind=engine)
@app.post("/items/")
def create_item(name: str):
db = SessionLocal()
item = Item(name=name)
db.add(item)
db.commit()
db.refresh(item)
db.close()
return item
Django REST Framework
DRF integrates seamlessly with Django’s ORM. In the previous Item example, the Item model is a Django model, and the ItemViewSet uses the ORM to interact with the database:
from .models import Item
from .serializers import ItemSerializer
from rest_framework.viewsets import ModelViewSet
class ItemViewSet(ModelViewSet):
queryset = Item.objects.all()
serializer_class = ItemSerializer
Best Practices
FastAPI Best Practices
- Use Asynchronous Programming: Take advantage of FastAPI’s asynchronous capabilities for I/O - bound operations, such as database queries or external API calls.
- Proper Error Handling: Use FastAPI’s exception handling mechanisms to provide meaningful error messages to the clients.
- Data Modeling with Pydantic: Use Pydantic models for clear data validation and serialization.
Django REST Framework Best Practices
- Follow Django’s Design Patterns: Leverage Django’s built - in features like the ORM, authentication, and permission systems.
- Optimize Serializers: Avoid over - fetching data by carefully defining serializers. Use nested serializers sparingly.
- Use Caching: Implement caching mechanisms to improve the performance of your API.
Conclusion
Both FastAPI and Django REST Framework are powerful tools for building RESTful APIs in Python. FastAPI is a great choice when you need high - performance and want to take advantage of asynchronous programming. It is also suitable for microservices and projects where you want to have more control over the API implementation. On the other hand, Django REST Framework is ideal for projects that are already using Django or require seamless integration with Django’s ecosystem. It provides a high - level of abstraction and a lot of built - in functionality out of the box.
References
- FastAPI Documentation: https://fastapi.tiangolo.com/
- Django REST Framework Documentation: https://www.django-rest-framework.org/
- Django Documentation: https://docs.djangoproject.com/