Quando você instala o FastAPI com `pip install "fastapi[standard]"`, ele vem com o grupo `standard` de dependências opcionais:

Utilizado pelo Pydantic:

* [`email-validator`](https://github.com/JoshData/python-email-validator) - para validação de email.

Utilizado pelo Starlette:

* [`httpx`](https://www.python-httpx.org) - Obrigatório caso você queira utilizar o `TestClient`.

Lorsque vous installez FastAPI avec `pip install "fastapi[standard]"`, il inclut le groupe `standard` de dépendances optionnelles :

Utilisées par Pydantic :

* [`email-validator`](https://github.com/JoshData/python-email-validator) - pour la validation des adresses e-mail.

Utilisées par Starlette :

* [`httpx`](https://www.python-httpx.org) - Obligatoire si vous souhaitez utiliser le `TestClient`.

    name: "Validation"
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - uses: gradle/actions/wrapper-validation@v5
      - name: Validate Renovate
        uses: rinchsan/renovate-config-validator@v0.2.0
        with:
          pattern: '.github/renovate.json'

  checks:
    permissions:
      checks: write # for mikepenz/action-junit-report
    runs-on: ubuntu-latest

    steps:

FastAPI'ı `pip install "fastapi[standard]"` ile yüklediğinizde, opsiyonel bağımlılıkların `standard` grubuyla birlikte gelir:

Pydantic tarafından kullanılanlar:

* [`email-validator`](https://github.com/JoshData/python-email-validator) - email doğrulaması için.

Starlette tarafından kullanılanlar:

* [`httpx`](https://www.python-httpx.org) - `TestClient` kullanmak istiyorsanız gereklidir.

* **복잡한 구조**를 검증합니다:
    * 계층적인 Pydantic 모델, Python `typing`의 `List`와 `Dict` 등을 사용합니다.
    * 그리고 validator는 복잡한 데이터 스키마를 명확하고 쉽게 정의하고, 검사하고, JSON Schema로 문서화할 수 있게 해줍니다.
    * 깊게 **중첩된 JSON** 객체를 가질 수 있으며, 이를 모두 검증하고 주석을 달 수 있습니다.
* **확장 가능**:
    * Pydantic은 사용자 정의 데이터 타입을 정의할 수 있게 하거나, validator decorator가 붙은 모델 메서드로 검증을 확장할 수 있습니다.

    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.
    * You can have deeply **nested JSON** objects and have them all validated and annotated.
* **Extensible**:
    * Pydantic allows custom data types to be defined or you can extend validation with methods on a model decorated with the validator decorator.

### `standard` Dependencies

When you install FastAPI with `pip install "fastapi[standard]"` it comes with the `standard` group of optional dependencies:

Used by Pydantic:

* [`email-validator`](https://github.com/JoshData/python-email-validator) - for email validation.

Used by Starlette:

* [`httpx`](https://www.python-httpx.org) - Required if you want to use the `TestClient`.

            stk.push(new ActivationFrame("arch", Optional.empty()));
            validator.accept(oa.getArch());
            stk.peek().location = "family";
            validator.accept(oa.getFamily());
            stk.peek().location = "name";
            validator.accept(oa.getName());
            stk.peek().location = "version";
            validator.accept(oa.getVersion());
            stk.pop();
            stk.pop();

When you install FastAPI with `pip install "fastapi[standard]"` it comes with the `standard` group of optional dependencies:

Used by Pydantic:

* [`email-validator`](https://github.com/JoshData/python-email-validator) - for email validation.

Used by Starlette:

* [`httpx`](https://www.python-httpx.org) - Required if you want to use the `TestClient`.

在这些情况下，你可以使用**自定义校验函数**，该函数会在正常校验之后应用（例如，在先校验值是 `str` 之后）。

你可以在 `Annotated` 中使用 [Pydantic 的 `AfterValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator) 来实现。

/// tip | 提示

Pydantic 还有 [`BeforeValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator) 等。🤓

///