REST API Development & FastAPI
Create high-performance APIs with FastAPI and understand RESTful principles.
FastAPI: Modern & High Performance
FastAPI is a modern web framework for building APIs with Python 3.7+ based on standard Python type hints.
Key Features
- Fast: Very high performance, on par with NodeJS and Go.
- Fast to code: Increase speed to develop features by about 200% to 300%.
- Fewer bugs: Reduce about 40% of human induced errors.
- Automatic Docs: Interactive API documentation (Swagger UI / ReDoc) out of the box.
Hello FastAPI
from fastapi import FastAPI
app = FastAPI()
@app.get("/")
async def read_root():
return {"Hello": "World"}
app = FastAPI()
@app.get("/")
async def read_root():
return {"Hello": "World"}
Path and Query Parameters
FastAPI uses Python type hints for validation and documentation.
@app.get("/items/<item_id>")
def read_item(item_id: int, q: str = None):
return {"item_id": item_id, "q": q}
def read_item(item_id: int, q: str = None):
return {"item_id": item_id, "q": q}
Pydantic Models
Define request bodies using Pydantic classes for automatic validation.
from pydantic import BaseModel
class Item(BaseModel):
name: str
price: float
@app.post("/items/")
def create_item(item: Item):
return item
class Item(BaseModel):
name: str
price: float
@app.post("/items/")
def create_item(item: Item):
return item
✅ Practice (30 minutes)
- Install FastAPI and Uvicorn:
pip install fastapi uvicorn. - Run your app:
uvicorn main:app --reload. - Visit
/docsto see the automatic Swagger UI. - Create an endpoint that accepts a list of IDs and returns their sum.