///

### Pydantic v1 and v2 on the same app { #pydantic-v1-and-v2-on-the-same-app }

It's **not supported** by Pydantic to have a model of Pydantic v2 with its own fields defined as Pydantic v1 models or vice versa.

```mermaid
graph TB
    subgraph "❌ Not Supported"
        direction TB
        subgraph V2["Pydantic v2 Model"]
            V1Field["Pydantic v1 Model"]
        end

{* ../../docs_src/events/tutorial001_py39.py hl[8] *}

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

We might want to separate between installation and activation, it might be nice to allow a user to activate/deactivate a plugin instead of having to uninstall and reinstall a plugin in particular cases. This would prevent having to reconfigure the plugin again. For example it might be nice to turn off LDAP authentication without having to uninstall the plugin.

* 自動ドキュメントシステムで使用されます。

しかし、最も重要なのは:

* 出力データをモデルのデータに限定します。これがどのように重要なのか以下で見ていきましょう。

/// note | 技術詳細

レスポンスモデルは、関数の戻り値のアノテーションではなく、このパラメータで宣言されています。なぜなら、パス関数は実際にはそのレスポンスモデルを返すのではなく、`dict`やデータベースオブジェクト、あるいは他のモデルを返し、`response_model`を使用してフィールドの制限やシリアライズを行うからです。

///

## 同じ入力データの返却

ここでは`UserIn`モデルを宣言しています。それには平文のパスワードが含まれています:

{* ../../docs_src/response_model/tutorial002.py hl[9,11] *}

어느 곳에서나 선택적 구성이 가능한 모든 것에 합리적인 기본값이 설정되어 있습니다. 모든 매개변수는 여러분이 필요하거나, 원하는 API를 정의하기 위해 미세하게 조정할 수 있습니다.

하지만 기본적으로 모든 것이 "그냥 작동합니다".

### 검증

* 다음을 포함한, 대부분의 (혹은 모든?) 파이썬 **데이터 타입** 검증할 수 있습니다:
    * JSON 객체 (`dict`).
    * 아이템 타입을 정의하는 JSON 배열 (`list`).
    * 최소 길이와 최대 길이를 정의하는 문자열 (`str`) 필드.
    * 최솟값과 최댓값을 가지는 숫자 (`int`, `float`), 그 외.

* 다음과 같이 더욱 이색적인 타입에 대해 검증할 수 있습니다:
    * URL.
    * 이메일.
    * UUID.

Führen wir unser vorheriges Beispiel fort. Wir wollten **die Funktion mit einem Typ annotieren**, aber wir wollten in der Funktion tatsächlich etwas zurückgeben, das **mehr Daten** enthält.

Wir möchten, dass FastAPI die Daten weiterhin mithilfe des Responsemodells **filtert**. Selbst wenn die Funktion mehr Daten zurückgibt, soll die Response nur die Felder enthalten, die im Responsemodell deklariert sind.

      // platforms in order to support Robolectric, which mixes classes from both Android and the
      // Oracle JDK. Note that we don't support HTTP/2 or other nice features on Robolectric.
      val sslContextClass = Class.forName("sun.security.ssl.SSLContextImpl")
      val context = readFieldOrNull(sslSocketFactory, sslContextClass, "context") ?: return null

        response = client.post(
            "/heroes/",
            json={
                "id": 9000,
                "name": "Dead Pond",
                "age": 30,
                "secret_name": "Dive Wilson",
            },
        )
        assert response.status_code == 200, response.text
        assert response.json() == snapshot(
            {"age": 30, "id": IsInt(), "name": "Dead Pond"}
        )

  /**
   * Returns a view of the complement of this {@code RangeSet}.
   *
   * <p>The returned view supports the {@link #add} operation if this {@code RangeSet} supports
   * {@link #remove}, and vice versa.
   */
  RangeSet<C> complement();

  /**
   * Returns a view of the intersection of this {@code RangeSet} with the specified range.
   *

Beachten Sie, dass die Fehlermeldung auch direkt die Stelle anzeigt, wo die Validierung nicht erfolgreich war.

Das ist unglaublich hilfreich, wenn Sie Code entwickeln und debuggen, welcher mit Ihrer API interagiert.

///

## Dokumentation { #documentation }