{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8:9] *}

Eso es todo.

**2 líneas**.

Y tiene la misma forma y estructura que todas tus *path operation functions*.

Puedes pensar en ella como una *path operation function* sin el "decorador" (sin el `@app.get("/some-path")`).

Y puede devolver lo que quieras.

	healthRouter.Methods(http.MethodGet).Path(healthCheckClusterPath).HandlerFunc(httpTraceAll(ClusterCheckHandler))
	healthRouter.Methods(http.MethodHead).Path(healthCheckClusterPath).HandlerFunc(httpTraceAll(ClusterCheckHandler))
	healthRouter.Methods(http.MethodGet).Path(healthCheckClusterReadPath).HandlerFunc(httpTraceAll(ClusterReadCheckHandler))

Вы можете определить параметры заголовка таким же образом, как вы определяете параметры `Query`, `Path` и `Cookie`.

## Импорт `Header`

Сперва импортируйте `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Объявление параметров `Header`

Затем объявите параметры заголовка, используя ту же структуру, что и с `Path`, `Query` и `Cookie`.

    /**
     * Returns the path of the file previously associated to this artifact
     * or {@code Optional.empty()} if no path has been associated.
     */
    @Nonnull
    Optional<Path> getPath(@Nonnull Artifact artifact);

    /**
     * Associates the given file path to the artifact.
     */
    void setPath(@Nonnull ProducedArtifact artifact, Path path);

		{"http://server/path?location", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format")},
		{"http://:/path", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format: invalid port number")},
		{"http://:8080/path", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format: empty host name")},
		{"http://server:/path", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format: invalid port number")},

<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components>
	<include path="convention.xml" />
	<include path="lastaflute_core.xml"/>
	<include path="fess.xml" />

	<include path="crawler_opensearch.xml" />
	<include path="fess_thumbnail.xml"/>

這意味著從環境變數中讀取的**任何值**在 Python 中都將是一個 `str`，任何型別轉換或驗證都必須在程式碼中完成。

你將在[進階使用者指南 - 設定和環境變數](./advanced/settings.md)中了解更多關於使用環境變數處理**應用程式設定**的資訊。

## `PATH` 環境變數

有一個**特殊的**環境變數稱為 **`PATH`**，作業系統（Linux、macOS、Windows）用它來查找要執行的程式。

`PATH` 變數的值是一個長字串，由 Linux 和 macOS 上的冒號 `:` 分隔的目錄組成，而在 Windows 上則是由分號 `;` 分隔的。

例如，`PATH` 環境變數可能如下所示：

//// tab | Linux, macOS

```plaintext
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
```

     * Removes the extension from the path.
     *
     * @param path
     *            The path. Must not be {@literal null}.
     * @return The path without the extension.
     */
    public static String removeExtension(final String path) {
        assertArgumentNotNull("path", path);

        final int extPos = path.lastIndexOf(".");
        if (extPos >= 0) {
            return path.substring(0, extPos);
        }

        assertEquals("Singleton context is already initialized", e.getMessage());
    }

    @Test
    void testInitLoadsJcifsPropertiesFile(@TempDir Path tempDir) throws IOException, CIFSException {
        // Test that jcifs.properties file is loaded
        Path jcifsPropertiesPath = tempDir.resolve("jcifs.properties");
        Files.writeString(jcifsPropertiesPath, "jcifs.smb.client.nativeOs=FileOS");

* Fix support for *paths* in *path parameters* without needing explicit `Path(...)`.
    * PR [#256](https://github.com/tiangolo/fastapi/pull/256).
    * Documented in PR [#272](https://github.com/tiangolo/fastapi/pull/272) by [@wshayes](https://github.com/wshayes).
    * New documentation at: [Path Parameters containing paths](https://fastapi.tiangolo.com/tutorial/path-params/#path-parameters-containing-paths).