- `externalDocs`：一个 `dict`，描述外部文档，包含：
    - `description`：一个 `str`，该外部文档的简短描述。
    - `url`（必填）：一个 `str`，该外部文档的 URL。

### 创建标签元数据 { #create-metadata-for-tags }

让我们在带有标签的示例中为 `users` 和 `items` 试一下。

创建标签元数据并把它传递给 `openapi_tags` 参数：

{* ../../docs_src/metadata/tutorial004_py310.py hl[3:16,18] *}

注意你可以在描述内使用 Markdown，例如「login」会显示为粗体（**login**）以及「fancy」会显示为斜体（_fancy_）。

/// tip | 提示

                                            <tbody>
                                            <c:forEach var="data" varStatus="s"
                                                       items="${accessTokenItems}">
                                                <tr
                                                        data-href="${contextPath}/admin/accesstoken/details/4/${f:u(data.id)}" role="button" tabindex="0">

///

`response_model` receives the same type you would declare for a Pydantic model field, so, it can be a Pydantic model, but it can also be, e.g. a `list` of Pydantic models, like `List[Item]`.

FastAPI will use this `response_model` to do all the data documentation, validation, etc. and also to **convert and filter the output data** to its type declaration.

/// tip

///

`response_model` recebe o mesmo tipo que você declararia para um campo de modelo Pydantic, então, pode ser um modelo Pydantic, mas também pode ser, por exemplo, uma `list` de modelos Pydantic, como `List[Item]`.

O FastAPI usará este `response_model` para fazer toda a documentação de dados, validação, etc. e também para **converter e filtrar os dados de saída** para sua declaração de tipo.

/// tip | Dica

    * Si la donnée est invalide, une erreur propre et claire sera renvoyée, indiquant exactement où et quelle était la donnée incorrecte.
* Passer la donnée reçue dans le paramètre `item`.
    * Ce paramètre ayant été déclaré dans la fonction comme étant de type `Item`, vous aurez aussi tout le support offert par l'éditeur (autocomplétion, etc.) pour tous les attributs de ce paramètre et les types de ces attributs.

o:o});if(r("slide.bs.carousel").defaultPrevented)return;if(!s||!n)return;const a=Boolean(this._interval);this.pause(),this._isSliding=!0,this._setActiveIndicatorElement(o),this._activeElement=n;const l=i?"carousel-item-start":"carousel-item-end",c=i?"carousel-item-next":"carousel-item-prev";n.classList.add(c),g(n),s.classList.add(l),n.classList.add(l),this._queueCallback((()=>{n.classList.remove(l,c),n.classList.add(ot),s.classList.remove(ot,c,l),this._isSliding=!1,r(it)}),s,this._isAnimated()),...

                                            <tbody>
                                            <c:forEach var="logFile" varStatus="s"
                                                       items="${logFileItems}">
                                                <tr
                                                        data-href="${contextPath}/admin/log/download/${f:u(logFile.id)}/">

 * features}, the features supported by the iterator; and {@code expectedElements}, the elements the
 * iterator should return in order.
 *
 * <p>The items in {@code elementsToInsert} will be repeated if {@code steps} is larger than the
 * number of provided elements.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@NullMarked

```JSON hl_lines="22"
{
    "openapi": "3.1.0",
    "info": {
        "title": "FastAPI",
        "version": "0.1.0"
    },
    "paths": {
        "/items/": {
            "get": {
                "summary": "Read Items",
                "operationId": "read_items_items__get",
                "responses": {
                    "200": {
                        "description": "Successful Response",

                                                <tbody>
                                                <c:forEach var="data" varStatus="s"
                                                           items="${requestHeaderItems}">
                                                    <tr
                                                            data-href="${contextPath}/admin/reqheader/details/4/${f:u(data.id)}">