```

### `RequestValidationError` vs `ValidationError`

/// warning | 警告

如果您觉得现在还用不到以下技术细节，可以先跳过下面的内容。

///

`RequestValidationError` 是 Pydantic 的 <a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a> 的子类。

**FastAPI** 调用的就是 `RequestValidationError` 类，因此，如果在 `response_model` 中使用 Pydantic 模型，且数据有错误时，在日志中就会看到这个错误。

Zusätzliche optionale Pydantic-Abhängigkeiten:

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> – für die Verwaltung von Einstellungen.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> – für zusätzliche Typen zur Verwendung mit Pydantic.

이를 위해 표준 Python 타입 힌트인 <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>을 사용할 수 있습니다:

/// note | 참고

<a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>을 정의할때는 더 구체적인 타입을 먼저 포함하고, 덜 구체적인 타입을 그 뒤에 나열해야합니다. 아래 예제에서는 `Union[PlaneItem, CarItem]` 를 보면, 더 구체적인 `PlaneItem`이 `CarItem`보다 앞에 위치합니다.

///

type DecryptRequest struct {
	// Name is the name of the master key used decrypt
	// the ciphertext.
	Name string

	// Version is the version of the master used for
	// decryption. If empty, the latest key version
	// is used.
	Version int

	// Ciphertext is the encrypted data that gets
	// decrypted.
	Ciphertext []byte

	// AssociatedData is the crypto. associated data.

/// info | Информация

Если вы уже прошли всё руководство и вернулись, чтобы узнать больше о типах, хорошим ресурсом будет <a href="https://mypy.readthedocs.io/en/latest/cheat_sheet_py3.html" class="external-link" target="_blank">«шпаргалка» от `mypy`</a>.

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.

To see all the options you have, checkout <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">Pydantic's Type Overview</a>. You will see some examples in the next chapter.

Чтобы увидеть все варианты, которые у вас есть, ознакомьтесь с <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">обзором типов Pydantic</a>. Вы увидите некоторые примеры в следующей главе.

/// check | Inspired **FastAPI** to

Use code to define "schemas" that provide data types and validation, automatically.

///

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webargs</a> { #webargs }

Another big feature required by APIs is <abbr title="reading and converting to Python data">parsing</abbr> data from incoming requests.

Sie können dies mit <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator" class="external-link" target="_blank">Pydantic's `AfterValidator`</a> innerhalb von `Annotated` erreichen.

/// tip | Tipp

Você pode fazer isso usando o <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator" class="external-link" target="_blank">`AfterValidator` do Pydantic</a> dentro de `Annotated`.

/// tip | Dica

O Pydantic também tem <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator" class="external-link" target="_blank">`BeforeValidator`</a> e outros. 🤓