How can I implement validation in FastAPI?

How can I implement validation in FastAPI?

You can use Pydantic models to define your data structure and validate input data in FastAPI.

Can you show me a simple example of a Pydantic model?

Sure! Here's a basic example:

from pydantic import BaseModel

class Item(BaseModel):
    name: str
    price: float
    is_offer: bool = None

How do I use this model in a FastAPI endpoint?

You can use it like this:

from fastapi import FastAPI

app = FastAPI()

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

What happens if the validation fails?

If validation fails, FastAPI will automatically return a 422 Unprocessable Entity response with details about the validation errors.