### 提供 `root_path`

为此，要以如下方式使用命令行选项 `--root-path`：

<div class="termy">

```console
$ uvicorn main:app --root-path /api/v1

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

</div>

Hypercorn 也支持 `--root-path `选项。

/// note | "技术细节"

ASGI 规范定义的 `root_path` 就是为了这种用例。

并且 `--root-path` 命令行选项支持 `root_path`。

///

Um dies zu erreichen, können Sie die Kommandozeilenoption `--root-path` wie folgt verwenden:

<div class="termy">

```console
$ uvicorn main:app --root-path /api/v1

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

</div>

Falls Sie Hypercorn verwenden, das hat auch die Option `--root-path`.

/// note | "Technische Details"

///

### Use your tags

Use the `tags` parameter with your *path operations* (and `APIRouter`s) to assign them to different tags:

```Python hl_lines="21  26"
{!../../docs_src/metadata/tutorial004.py!}
```

/// info

Read more about tags in [Path Operation Configuration](path-operation-configuration.md#tags){.internal-link target=_blank}.

///

### Check the docs

## `PATH` Omgevingsvariabele

Er is een **speciale** omgevingsvariabele met de naam **`PATH`**, die door de besturingssystemen (Linux, macOS, Windows) wordt gebruikt om programma's te vinden die uitgevoerd kunnen worden.

## `PATH` Environment Variable

There is a **special** environment variable called **`PATH`** that is used by the operating systems (Linux, macOS, Windows) to find programs to run.

The value of the variable `PATH` is a long string that is made of directories separated by a colon `:` on Linux and macOS, and by a semicolon `;` on Windows.

For example, the `PATH` environment variable could look like this:

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python
from fastapi import Body, Cookie, File, Form, Header, Path, Query
```

::: fastapi.Query

func (k *KeycloakProvider) LookupUser(userid string) (User, error) {
	req, err := http.NewRequest(http.MethodGet, k.adminURL, nil)
	if err != nil {
		return User{}, err
	}
	req.URL.Path = path.Join(req.URL.Path, "realms", k.realm, "users", userid)

	k.Lock()
	accessToken := k.accessToken
	k.Unlock()
	if accessToken.AccessToken == "" {
		return User{}, ErrAccessTokenExpired
	}

@needs_py310
@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),
        ("/items", {"User-Agent": "FastAPI test"}, 200, {"User-Agent": "FastAPI test"}),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):

            "/items",
            {"strange-header": "Not really underscore"},
            200,
            {"strange_header": None},
        ),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):
    response = client.get(path, headers=headers)
    assert response.status_code == expected_status
    assert response.json() == expected_response


@needs_py39
def test_openapi_schema():

Notice that here as we are using standard `open()` that doesn't support `async` and `await`, we declare the path operation with normal `def`.

///

### `FileResponse`

Asynchronously streams a file as the response.

Takes a different set of arguments to instantiate than the other response types:

* `path` - The file path to the file to stream.
* `headers` - Any custom headers to include, as a dictionary.