本例中，查询参数 `q` 是可选的，默认值为 `None`。

/// check | 检查

注意，**FastAPI** 可以识别出 `item_id` 是路径参数，`q` 不是路径参数，而是查询参数。

///

/// note | 笔记

因为默认值为 `= None`，FastAPI 把 `q` 识别为可选参数。

FastAPI 不使用 `Optional[str]` 中的 `Optional`（只使用 `str`），但 `Optional[str]` 可以帮助编辑器发现代码中的错误。

///

## 查询参数类型转换

参数还可以声明为 `bool` 类型，FastAPI 会自动转换参数类型：


{* ../../docs_src/query_params/tutorial003_py310.py hl[7] *}

# Test with parts from, and to verify the report in:
# https://github.com/fastapi/fastapi/discussions/14177
# Made an issue in:
# https://github.com/fastapi/fastapi/issues/14247
from enum import Enum

from fastapi import FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel, Field


class MessageEventType(str, Enum):
    alpha = "alpha"
    beta = "beta"

/// check | vérifier

Comme vous l'avez remarqué, la valeur reçue par la fonction (et renvoyée ensuite) est `3`,
en tant qu'entier (`int`) Python, pas la chaîne de caractères (`string`) `"3"`.

Grâce aux déclarations de types, **FastAPI** fournit du
<abbr title="conversion de la chaîne de caractères venant de la requête HTTP en données Python">"parsing"</abbr> automatique.

///

## Validation de données

Örneğin `pip install python-multipart`.

///

## `Form` Sınıfını Projenize Dahil Edin

`Form` sınıfını `fastapi`'den projenize dahil edin:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[3] *}

## `Form` Parametrelerini Tanımlayın

Form parametrelerini `Body` veya `Query` için yaptığınız gibi oluşturun:

# Ref: https://github.com/fastapi/fastapi/issues/14454

from typing import Annotated

from fastapi import Depends, FastAPI, Security
from fastapi.security import OAuth2AuthorizationCodeBearer
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

oauth2_scheme = OAuth2AuthorizationCodeBearer(
    authorizationUrl="api/oauth/authorize",
    tokenUrl="/api/oauth/token",
    scopes={"read": "Read access", "write": "Write access"},

## Adım Adım Özetleyelim

### Adım 1: `FastAPI`yı Projemize Dahil Edelim

{* ../../docs_src/first_steps/tutorial001.py hl[1] *}

`FastAPI`, API'niz için tüm işlevselliği sağlayan bir Python sınıfıdır.

/// note | Teknik Detaylar

`FastAPI` doğrudan `Starlette`'i miras alan bir sınıftır.

Vous pouvez connecter le <abbr title="En anglais: debugger">débogueur</abbr> dans votre éditeur, par exemple avec Visual Studio Code ou PyCharm.

## Faites appel à `uvicorn`

Dans votre application FastAPI, importez et exécutez directement `uvicorn` :

{* ../../docs_src/debugging/tutorial001.py hl[1,15] *}

### À propos de `__name__ == "__main__"`

---

Por exemplo, no Visual Studio Code, você pode:

* Ir para o painel "Debug".
* "Add configuration...".
* Selecionar "Python"
* Executar o depurador com a opção "`Python: Current File (Integrated Terminal)`".

Em seguida, ele iniciará o servidor com seu código **FastAPI**, parará em seus pontos de interrupção, etc.

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel

# to get a string like this run:
# openssl rand -hex 32

from fastapi import FastAPI
from fastapi.responses import RedirectResponse

app = FastAPI()


@app.get("/fastapi", response_class=RedirectResponse)
async def redirect_fastapi():