- Automatic Data Validation: FastAPI uses Python type hints to automatically validate request and response data, reducing the need for manual input validation code.
- Automatic API Documentation: FastAPI generates interactive API documentation using tools like Swagger and ReDoc. This documentation is updated in real-time based on your code and type hints, making it easier for developers to understand and test your API.
- Asynchronous Support: FastAPI supports asynchronous programming, allowing you to write asynchronous endpoints using Python’s
async
andawait
keywords. This is particularly useful for handling I/O-bound operations, such as database queries. - Dependency Injection: You can use FastAPI’s dependency injection system to manage and share components like database connections, authentication, and authorization logic across your application.
- Request and Response Models: You can define models for request and response data using Pydantic, a library for data validation and parsing. FastAPI will automatically validate and serialize these models for you.
- Middleware: FastAPI supports middleware, which allows you to customize and extend the behavior of your application by adding functionality like logging, authentication, or CORS handling.
- Background Tasks: You can schedule and run background tasks in FastAPI, which is useful for executing tasks asynchronously, such as sending emails or processing data.
- WebSocket Support: FastAPI also has support for WebSocket connections, enabling real-time communication between clients and your server.
To get started with FastAPI, you typically create Python functions for your API endpoints and decorate them with FastAPI-specific decorators. Here’s a simple example of a FastAPI application:
pythonCopy codefrom fastapi import FastAPI
app = FastAPI()
@app.get("/")
def read_root():
return {"message": "Hello, FastAPI"}
@app.get("/items/{item_id}")
def read_item(item_id: int, query_param: str = None):
return {"item_id": item_id, "query_param": query_param}
You can install FastAPI using pip:
bashCopy codepip install fastapi
FastAPI has become a popular choice for building web APIs and applications due to its performance, ease of use, and the ability to leverage Python’s type hinting system to improve code quality and documentation.