* Wenn Sie Starlette vergleichen, vergleichen Sie es mit Webframeworks (oder Mikroframeworks) wie Sanic, Flask, Django, usw.
* **FastAPI**:
    * So wie Starlette Uvicorn verwendet und nicht schneller als dieses sein kann, verwendet **FastAPI** Starlette, sodass es nicht schneller als dieses sein kann.

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


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

from dataclasses import dataclass

from fastapi import FastAPI


@dataclass
class Item:
    name: str
    price: float
    description: str | None = None
    tax: float | None = None


app = FastAPI()


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

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    hidden_query: Annotated[str | None, Query(include_in_schema=False)] = None,
):
    if hidden_query:
        return {"hidden_query": hidden_query}
    else:

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(default=None, alias="item-query")):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

/// tip

FastAPI automatically generates **OpenAPI 3.1** specifications, so any tool you use must support this version.

///

## SDK Generators from FastAPI Sponsors { #sdk-generators-from-fastapi-sponsors }

Isto é suportado desde a versão `0.113.0` do FastAPI. 🤓

///

## Modelos Pydantic para Formulários { #pydantic-models-for-forms }

Você precisa apenas declarar um **modelo Pydantic** com os campos que deseja receber como **campos de formulários**, e então declarar o parâmetro como um `Form`:

{* ../../docs_src/request_form_models/tutorial001_an_py39.py hl[9:11,15] *}

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel


class ResponseModel(BaseModel):
    message: str


app = FastAPI()
router = APIRouter()


@router.get("/a", responses={501: {"description": "Error 1"}})
async def a():
    return "a"


@router.get(
    "/b",
    responses={
        502: {"description": "Error 2"},

# Unteranwendungen – Mounts { #sub-applications-mounts }

Wenn Sie zwei unabhängige FastAPI-Anwendungen mit deren eigenen unabhängigen OpenAPI und deren eigenen Dokumentationsoberflächen benötigen, können Sie eine Hauptanwendung haben und dann eine (oder mehrere) Unteranwendung(en) „mounten“.

## Eine **FastAPI**-Anwendung mounten { #mounting-a-fastapi-application }

from fastapi import APIRouter, FastAPI, Request
from fastapi.responses import JSONResponse
from fastapi.testclient import TestClient

app = FastAPI()
router = APIRouter()


@router.route("/items/")
def read_items(request: Request):
    return JSONResponse({"hello": "world"})


app.include_router(router)

client = TestClient(app)


def test_sub_router():
    response = client.get("/items/")