The second version is an "absolute import":

    ```Python
    from app.routers import items, users
    ```

    To learn more about Python Packages and Modules, read <a href="https://docs.python.org/3/tutorial/modules.html" class="external-link" target="_blank">the official Python documentation about Modules</a>.

### Avoid name collisions

We are importing the submodule `items` directly, instead of importing just its variable `router`.

## 0.5.1

* Add section about [helping and getting help with **FastAPI**](https://fastapi.tiangolo.com/help-fastapi/).

* Add note about [path operations order in docs](https://fastapi.tiangolo.com/tutorial/path-params/#order-matters).

### Technische Details: `root_path`

Wenn Sie eine Unteranwendung wie oben beschrieben mounten, kümmert sich FastAPI darum, den Mount-Pfad für die Unteranwendung zu kommunizieren, mithilfe eines Mechanismus aus der ASGI-Spezifikation namens `root_path`.

    assert response.json() == {"msg": "Create an account first"}


def test_security_http_bearer_incorrect_scheme_credentials():
    response = client.get("/users/me", headers={"Authorization": "Basic notreally"})
    assert response.status_code == 200, response.text
    assert response.json() == {"msg": "Create an account first"}


def test_openapi_schema():
    response = client.get("/openapi.json")

    if token is None:
        return {"msg": "Create an account first"}
    return {"token": token}


client = TestClient(app)


def test_no_token():
    response = client.get("/items")
    assert response.status_code == 200, response.text
    assert response.json() == {"msg": "Create an account first"}


def test_token():

# WSGI inkludieren – Flask, Django und andere

Sie können WSGI-Anwendungen mounten, wie Sie es in [Unteranwendungen – Mounts](sub-applications.md){.internal-link target=_blank}, [Hinter einem Proxy](behind-a-proxy.md){.internal-link target=_blank} gesehen haben.

Dazu können Sie die `WSGIMiddleware` verwenden und damit Ihre WSGI-Anwendung wrappen, zum Beispiel Flask, Django usw.

## `WSGIMiddleware` verwenden

Sie müssen `WSGIMiddleware` importieren.

!!! tip
    All this might not seem as useful with these simple examples.

    But you will see how useful it is in the chapters about **security**.

You can write <a href="https://en.wikipedia.org/wiki/Markdown" class="external-link" target="_blank">Markdown</a> in the docstring, it will be interpreted and displayed correctly (taking into account docstring indentation).

=== "Python 3.10+"

    ```Python hl_lines="17-25"
    {!> ../../../docs_src/path_operation_configuration/tutorial004_py310.py!}
    ```

=== "Python 3.9+"

    * Read other ideas, articles, and read about tools I have created.
    * Follow me to read when I publish something new.

## Tweet about **FastAPI**

<a href="https://twitter.com/compose/tweet?text=I'm loving @fastapi because... https://github.com/tiangolo/fastapi" class="external-link" target="_blank">Tweet about **FastAPI**</a> and let me and others know why you like it. 🎉

!!! tip
    Pydantic, which is what powers all the data validation and serialization in FastAPI, has a special behavior when you use `Optional` or `Union[Something, None]` without a default value, you can read more about it in the Pydantic docs about <a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">Required Optional fields</a>.

!!! tip