Python FastAPI Tutorial

FastAPI is a modern Python web framework for building APIs.

Getting Started

Install FastAPI and Uvicorn:

pip install fastapi uvicorn

Basic Application

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):
    return {"item_id": item_id}

Run the Server

uvicorn main:app --reload

Type Hints and Validation

from pydantic import BaseModel

class Item(BaseModel):
    name: str
    price: float
    is_offer: bool = False

@app.post("/items/")
def create_item(item: Item):
    return item

Automatic Documentation

FastAPI generates interactive API documentation:

• Swagger UI at /docs
• ReDoc at /redoc

Conclusion

FastAPI makes building high-performance Python APIs easy and enjoyable.