{!../../docs_src/query_params_str_validations/tutorial006c.py!}
```

/// tip

Pydantic 是 FastAPI 中所有数据验证和序列化的核心，当你在没有设默认值的情况下使用 `Optional` 或 `Union[Something, None]` 时，它具有特殊行为，你可以在 Pydantic 文档中阅读有关<a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">必需可选字段</a>的更多信息。

///

### 使用Pydantic中的`Required`代替省略号(`...`)

如果你觉得使用 `...` 不舒服，你也可以从 Pydantic 导入并使用 `Required`：

apiVersion: v1 appVersion: RELEASE.2022-08-05T23-27-09Z description: Multi-Cloud Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 4.0.11 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...

apiVersion: v1 appVersion: RELEASE.2022-05-08T23-50-31Z description: Multi-Cloud Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 4.0.2 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...

apiVersion: v1 appVersion: RELEASE.2022-05-08T23-50-31Z description: Multi-Cloud Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 4.0.3 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...

apiVersion: v1 appVersion: RELEASE.2022-10-24T18-35-07Z description: Multi-Cloud Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 5.0.0 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...

cel.dev/expr v0.16.0 h1:yloc84fytn4zmJX2GU3TkXGsaieaV7dQ057Qs4sIG2Y=
cel.dev/expr v0.16.0/go.mod h1:TRSuuV7DlVCE/uwv5QbAiW/v8l5O8C4eEPHeu7gf7Sg=
cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
cloud.google.com/go/compute/metadata v0.5.2 h1:UxK4uu/Tn+I3p2dYWTfiX4wva7aYlKixAHn3fyqngqo=
cloud.google.com/go/compute/metadata v0.5.2/go.mod h1:C66sj2AluDcIqakBq/M8lw8/ybHgOZqin2obFxa/E5k=

 * use a framework. Frameworks automate the process, often adding features like monitoring,
 * debugging, and cancellation. Examples of frameworks include:
 *
 * <ul>
 *   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>
 * </ul>
 *
 * <h4>{@link java.util.concurrent.CompletableFuture} / {@link java.util.concurrent.CompletionStage}
 * </h4>
 *

## Зависимости

FastAPI стоит на плечах гигантов:

* <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> для части связанной с вебом.
* <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> для части связанной с данными.

## Установка

<div class="termy">

```console
$ pip install fastapi

---> 100%
```

</div>

appVersion: RELEASE.2024-04-18T19-09-19Z description: High Performance Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 5.3.0 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...

apiVersion: v1 appVersion: RELEASE.2021-09-09T21-37-07Z description: Multi-Cloud Object Storage home: https://min.io icon: https://min.io/resources/img/logo/MINIO_wordmark.png keywords: - minio - storage - object-storage - s3 - cluster maintainers: - email: dev@minio.io name: MinIO, Inc name: minio sources: - https://github.com/minio/minio version: 3.1.2 minio/values.yaml ## Provide a name in place of minio for `app:` labels ## nameOverride: "" ## Provide a name to substitute for the full names of resources...