`Header` 與 `Path`、`Query`、`Cookie` 是「姊妹」類別，同樣繼承自共同的 `Param` 類別。

但請記得，當你從 `fastapi` 匯入 `Query`、`Path`、`Header` 等時，它們其實是會回傳特殊類別的函式。

///

/// info | 說明

要宣告標頭，必須使用 `Header`，否則參數會被解讀為查詢參數。

///

## 自動轉換 { #automatic-conversion }

在 `Path`、`Query`、`Cookie` 提供的功能之上，`Header` 還有一些額外的小功能。

大多數標準標頭的單字以連字號（減號，`-`）分隔。

但像 `user-agent` 這樣的變數名稱在 Python 中是無效的。

因此，`Header` 會在預設情況下把參數名稱中的底線（`_`）轉換為連字號（`-`），以便讀取並在文件中顯示該標頭。

## 为 JavaScript 和 CSS 自定义 CDN { #custom-cdn-for-javascript-and-css }

假设你想使用不同的 <abbr title="Content Delivery Network - 内容分发网络">CDN</abbr>，例如使用 `https://unpkg.com/`。

如果你所在的国家/地区屏蔽了某些 URL，这会很有用。

### 关闭自动文档 { #disable-the-automatic-docs }

第一步是关闭自动文档，因为默认它们会使用默认的 CDN。

要关闭它们，在创建 `FastAPI` 应用时将其 URL 设为 `None`：

{* ../../docs_src/custom_docs_ui/tutorial001_py310.py hl[8] *}

### 包含自定义文档 { #include-the-custom-docs }

But you can still document it as described in [Additional Responses in OpenAPI](additional-responses.md).

최상위 애플리케이션 `app`에서 하위 애플리케이션 `subapi`를 마운트합니다.

이 경우 `/subapi` 경로에 마운트됩니다:

{* ../../docs_src/sub_applications/tutorial001_py310.py hl[11, 19] *}

### 자동 API 문서 확인 { #check-the-automatic-api-docs }

이제 `fastapi` 명령어를 실행하세요:

<div class="termy">

```console
$ fastapi dev

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

This way, you can do the upgrade and make sure everything is still working as expected.

## `bump-pydantic` { #bump-pydantic }

In many cases, when you use regular Pydantic models without customizations, you will be able to automate most of the process of migrating from Pydantic v1 to Pydantic v2.

You can use [`bump-pydantic`](https://github.com/pydantic/bump-pydantic) from the same Pydantic team.

     * allowed. But at the same time, it seems wasteful to bother inserting the checkNotNull calls
     * that NullPointerTester wants.
     *
     * (This empty method disables the automatic null testing provided by PackageSanityTests.)
     */
  }

            handleManager.releaseHandle(getPath());
        }
    }
}

// Handle network errors with automatic reconnection
@Override
protected void handleNetworkError(IOException e) {
    if (handleType != null && handleType != HandleType.NONE) {
        // Attempt automatic reconnection
        HandleReconnector reconnector = new HandleReconnector(handleManager);
        try {

 * (or {@link FluentFuture#transform(com.google.common.base.Function, Executor)
 * FluentFuture.transform}), but you will often find it easier to use a framework. Frameworks
 * automate the process, often adding features like monitoring, debugging, and cancellation.
 * Examples of frameworks include:
 *
 * <ul>
 *   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>
 * </ul>
 *

esac

# Link in architecture specific includes from the system; note that we cannot
# link in the whole x86_64-linux-gnu folder, as otherwise we're overlaying
# system gcc paths that we do not want to find.
# TODO(klimek): Automate linking in all non-gcc / non-kernel include
# directories.
mkdir -p "/${TARGET}/usr/include/x86_64-linux-gnu"
PYTHON_VERSIONS=("python3.10" "python3.11" "python3.12")
for v in "${PYTHON_VERSIONS[@]}"; do

     * allowed. But at the same time, it seems wasteful to bother inserting the checkNotNull calls
     * that NullPointerTester wants.
     *
     * (This empty method disables the automatic null testing provided by PackageSanityTests.)
     */
  }