En el capítulo anterior, el sistema de seguridad (que se basa en el sistema de inyección de dependencias) le estaba dando a la *path operation function* un `token` como un `str`:

{* ../../docs_src/security/tutorial001_an_py39.py hl[12] *}

Pero eso aún no es tan útil. Vamos a hacer que nos dé el usuario actual.

## Crear un modelo de usuario { #create-a-user-model }

Primero, vamos a crear un modelo de usuario con Pydantic.

import importlib

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient


@pytest.fixture(
    name="app",
    params=[
        "tutorial001_py39",
        "tutorial001_an_py39",
    ],
)
def get_app(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.request_forms_and_files.{request.param}")

    return mod.app


@pytest.fixture(name="client")

    default_registry.dispose()


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_an_py39"),
        pytest.param("tutorial001_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    clear_sqlmodel()
    # TODO: remove when updating SQL tutorial to use new lifespan API

Nehmen wir an, Sie möchten, dass der `q` Query-Parameter eine `min_length` von `3` hat und einen Defaultwert von `"fixedquery"`:

{* ../../docs_src/query_params_str_validations/tutorial005_an_py39.py hl[9] *}

/// note | Hinweis

Ein Defaultwert irgendeines Typs, einschließlich `None`, macht den Parameter optional (nicht erforderlich).

///

## Erforderliche Parameter { #required-parameters }

Digamos que você queira declarar o parâmetro de consulta `q` com `min_length` de `3` e ter um valor padrão de `"fixedquery"`:

{* ../../docs_src/query_params_str_validations/tutorial005_an_py39.py hl[9] *}

/// note | Nota

Ter um valor padrão de qualquer tipo, incluindo `None`, torna o parâmetro opcional (não obrigatório).

///

## Parâmetros obrigatórios { #required-parameters }

//// tab | Python 3.10+

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13, 15, 22, 25] *}

////

//// tab | Python 3.9+

{* ../../docs_src/background_tasks/tutorial002_an_py39.py hl[13, 15, 22, 25] *}

////

//// tab | Python 3.8+

{* ../../docs_src/background_tasks/tutorial002_an.py hl[14, 16, 23, 26] *}

////

//// tab | Python 3.10+ 没Annotated

/// tip

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial004_py39"),
        pytest.param("tutorial004_py310", marks=needs_py310),
        pytest.param("tutorial004_an_py39"),
        pytest.param("tutorial004_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_multiple_params.{request.param}")

Pydantic의 모델 구성을 사용하여 추가(`extra`) 필드를 금지(`forbid`)할 수 있습니다:

{* ../../docs_src/cookie_param_models/tutorial002_an_py39.py hl[10] *}

클라이언트가 **추가 쿠키**를 보내려고 시도하면, **오류** 응답을 받게 됩니다.

<abbr title="이건 또 다른 농담입니다. 제 말에 귀 기울이지 마세요. 커피랑 쿠키 좀 드세요. ☕">API가 거부</abbr>하는데도 동의를 얻기 위해 애쓰는 불쌍한 쿠키 배너(팝업)들. 🍪

Pydanticのモデルの Configuration を利用して、 `extra` フィールドを `forbid` とすることができます。

{* ../../docs_src/cookie_param_models/tutorial002_an_py39.py hl[10] *}

もしクライアントが**余分なクッキー**を送ろうとすると、**エラー**レスポンスが返されます。

# Get Current User { #get-current-user }

In the previous chapter the security system (which is based on the dependency injection system) was giving the *path operation function* a `token` as a `str`:

{* ../../docs_src/security/tutorial001_an_py39.py hl[12] *}

But that is still not that useful.

Let's make it give us the current user.

## Create a user model { #create-a-user-model }

First, let's create a Pydantic user model.