# JSON кодировщик

В некоторых случаях может потребоваться преобразование типа данных (например, Pydantic-модели) в тип, совместимый с JSON (например, `dict`, `list` и т.д.).

Например, если необходимо хранить его в базе данных.

Для этого **FastAPI** предоставляет функцию `jsonable_encoder()`.

## Использование `jsonable_encoder`

Представим, что у вас есть база данных `fake_db`, которая принимает только JSON-совместимые данные.

更新部分数据时，可以在 Pydantic 模型的 `.dict()` 中使用 `exclude_unset` 参数。

比如，`item.dict(exclude_unset=True)`。

这段代码生成的 `dict` 只包含创建 `item` 模型时显式设置的数据，而不包括默认值。

然后再用它生成一个只含已设置（在请求中所发送）数据，且省略了默认值的 `dict`：

```Python hl_lines="34"
{!../../docs_src/body_updates/tutorial002.py!}
```

### 使用 Pydantic 的 `update` 参数

接下来，用 `.copy()` 为已有模型创建调用 `update` 参数的副本，该参数为包含更新数据的 `dict`。

    <jsp:include page="/WEB-INF/view/common/admin/sidebar.jsp">
        <jsp:param name="menuCategoryType" value="system"/>
        <jsp:param name="menuType" value="dict"/>
    </jsp:include>
    <div class="content-wrapper">
        <div class="content-header">
            <div class="container-fluid">
                <div class="row mb-2">
                    <div class="col-sm-6">

```

////

//// tab | Python 3.10+ non-Annotated

/// tip | Dica

Prefira usar a versão `Annotated`, se possível.

///

```Python hl_lines="2  74"
{!> ../../docs_src/security/tutorial003_py310.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | Dica

Prefira usar a versão `Annotated`, se possível.

///

```Python hl_lines="4  76"

* `items_s` ise her öğesi `bytes` türünde olan bir `set` örneğidir.

#### `Dict`

Bir `dict` tanımlamak için virgülle ayrılmış iki parametre verebilirsiniz.

İlk tip parametresi `dict` değerinin `key` değeri içindir.

İkinci parametre ise `dict` değerinin `value` değeri içindir:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial008.py!}
```

# JSON-kompatibler Encoder

Es gibt Fälle, da möchten Sie einen Datentyp (etwa ein Pydantic-Modell) in etwas konvertieren, das kompatibel mit JSON ist (etwa ein `dict`, eine `list`e, usw.).

Zum Beispiel, wenn Sie es in einer Datenbank speichern möchten.

Dafür bietet **FastAPI** eine Funktion `jsonable_encoder()`.

## `jsonable_encoder` verwenden

Stellen wir uns vor, Sie haben eine Datenbank `fake_db`, die nur JSON-kompatible Daten entgegennimmt.

```

////

//// tab | Python 3.10+ non-Annotated

/// tip | Dica

Prefira utilizar a versão `Annotated` se possível.

///

```Python hl_lines="1"
{!> ../../docs_src/cookie_params/tutorial001_py310.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | Dica

Prefira utilizar a versão `Annotated` se possível.

///

```Python hl_lines="3"

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.dict.kuromoji;

import org.codelibs.fess.app.web.admin.dict.kuromoji.CreateForm;

public class CreateBody extends CreateForm {

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.dict.mapping;

import org.codelibs.fess.app.web.admin.dict.mapping.DownloadForm;

public class DownloadBody extends DownloadForm {

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.dict.mapping;

import org.codelibs.fess.app.web.admin.dict.mapping.EditForm;

public class EditBody extends EditForm {