## Champs de liste avec paramètre de type { #list-fields-with-type-parameter }

Mais Python a une manière spécifique de déclarer des listes avec des types internes, ou « paramètres de type » :

### Déclarer une `list` avec un paramètre de type { #declare-a-list-with-a-type-parameter }

Pour déclarer des types qui ont des paramètres de type (types internes), comme `list`, `dict`, `tuple`,

 *      </td>
 *   </tr>
 *   <tr>
 *      <td>parameters</td>
 *      <td>N/A</td>
 *      <td>No</td>
 *      <td>Specifications for the parameters which this Mojo uses will be provided in <b>parameter</b> sub-elements
 *          in this section.
 *          <br>
 *          <i>NOTE: Parameters are discussed in more detail below.</i>
 *      </td>
 *   </tr>
 * </table>

# Parámetros de Query y Validaciones de String { #query-parameters-and-string-validations }

**FastAPI** te permite declarar información adicional y validación para tus parámetros.

Tomemos esta aplicación como ejemplo:

{* ../../docs_src/query_params_str_validations/tutorial001_py310.py hl[7] *}

    public void add(final String name, final ScriptEngine scriptEngine) {
        if (name == null || scriptEngine == null) {
            throw new IllegalArgumentException(
                    "Both name and scriptEngine parameters are required. name: " + name + ", scriptEngine: " + scriptEngine);
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Loaded ScriptEngine: {}", name);
        }

## Pydantic Model ile Header Parametreleri { #header-parameters-with-a-pydantic-model }

İhtiyacınız olan **header parametreleri**ni bir **Pydantic model** içinde tanımlayın, ardından parametreyi `Header` olarak belirtin:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI**, request içindeki **headers** bölümünden **her alan** için veriyi **çıkarır** ve size tanımladığınız Pydantic model örneğini verir.

# Body - 多個參數 { #body-multiple-parameters }

現在我們已經知道如何使用 `Path` 與 `Query`，接下來看看更進階的請求主體（request body）宣告用法。

## 混用 `Path`、`Query` 與 Body 參數 { #mix-path-query-and-body-parameters }

首先，當然你可以自由混用 `Path`、`Query` 與請求 Body 參數的宣告，**FastAPI** 會知道該怎麼做。

你也可以將 Body 參數宣告為可選，方法是將預設值設為 `None`：

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note | 注意

請注意，在此情況下，從 body 取得的 `item` 是可選的，因為它的預設值是 `None`。

///

        assertEquals(testWindowSize, queryRescorerBuilder.windowSize().intValue());
    }

    @Test
    public void test_evaluate_withEmptyParams() {
        // Test with empty parameters map
        final String testModelName = "test_model";
        final int testWindowSize = 50;

        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            @Override

     * parameter type matches boolean primitive formal type). This behavior
     * is because this method is used to determine applicable methods for
     * an actual parameter list, and primitive types are represented by
     * their object duals in reflective method calls.
     *
     * @param formal the formal parameter type to which the actual

Declara los **parámetros de header** que necesitas en un **modelo Pydantic**, y luego declara el parámetro como `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI** **extraerá** los datos para **cada campo** de los **headers** en el request y te dará el modelo Pydantic que definiste.

## Revisa la Documentación { #check-the-docs }

Declare os **parâmetros de cabeçalho** que você precisa em um **modelo do Pydantic**, e então declare o parâmetro como `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

O **FastAPI** irá **extrair** os dados de **cada campo** a partir dos **cabeçalhos** da requisição e te retornará o modelo do Pydantic que você definiu.