```JSON
{"item_id":3}
```

/// check | 检查

注意，函数接收并返回的值是 `3`（ `int`），不是 `"3"`（`str`）。

**FastAPI** 通过类型声明自动<abbr title="将来自 HTTP 请求中的字符串转换为 Python 数据类型">**解析**请求中的数据</abbr>。

///

## 数据校验

## Beispiel { #example }

Betrachten wir als einfaches Beispiel eine Dateistruktur ähnlich der in [Größere Anwendungen](../tutorial/bigger-applications.md){.internal-link target=_blank} und [Testen](../tutorial/testing.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py

import java.lang.annotation.Target;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Used if your Mojo needs to fork a <a href="/ref/3.0.4/maven-core/lifecycles.html">lifecycle</a>.
 *
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Inherited
public @interface Execute {

/// info

To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

/// note

	CreationDate time.Time `json:"creationDate"`

	// When a SRV record with a "Host: IP-address" is added, we synthesize
	// a srv.Target domain name.  Normally we convert the full Key where
	// the record lives to a DNS name and use this as the srv.Target. When
	// TargetStrip > 0 we strip the left most TargetStrip labels from the
	// DNS name.
	TargetStrip int `json:"targetstrip,omitempty"`

		cfg.OpenID = openid.Config{}
		cfg.Policy.OPA = opa.Args{
			URL:       &xnet.URL{},
			AuthToken: "",
		}
	case "31":
		// V31 -> V32
		cfg.Notify.NSQ = make(map[string]target.NSQArgs)
		cfg.Notify.NSQ["1"] = target.NSQArgs{}
	}

	// Move to latest.
	cfg.Version = "33"

	newCfg := newServerConfig()

	config.SetRegion(newCfg, cfg.Region)
	storageclass.SetStorageClass(newCfg, cfg.StorageClass)

## Dokumentations-Tags – OpenAPI { #documentation-tags-openapi }

Um Tags zu Ihren *Pfadoperationen* hinzuzufügen und diese in der Oberfläche der Dokumentation zu gruppieren, lesen Sie die Dokumentation unter [Tutorial – Pfadoperation-Konfiguration – Tags](../tutorial/path-operation-configuration.md#tags){.internal-link target=_blank}.

## Tags de Documentação - OpenAPI { #documentation-tags-openapi }
Para adicionar tags às suas *operações de rota* e agrupá-las na UI da documentação, leia a seção [Tutorial - Configurações da Operação de Rota - Tags](../tutorial/path-operation-configuration.md#tags){.internal-link target=_blank}.

Відкрийте браузер та введіть адресу <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Ви побачите у відповідь таке повідомлення у форматі JSON:

```JSON
{"message": "Hello World"}
```

### Інтерактивна API документація

Перейдемо сюди <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

Pour en savoir plus à propos de <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic, allez jeter un coup d'oeil à sa documentation</a>.

///

**FastAPI** est basé entièrement sur **Pydantic**.

Vous verrez bien plus d'exemples de son utilisation dans [Tutoriel - Guide utilisateur](tutorial/index.md){.internal-link target=_blank}.

## Les annotations de type dans **FastAPI**