if not file:
        return {"message": "No file sent"}
    else:
        return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(file: Union[UploadFile, None] = None):
    if not file:
        return {"message": "No upload file sent"}
    else:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial008.py!}
```

Dans cet exemple :

* La variable `prices` est de type `dict` :
    * Les clés de ce dictionnaire sont de type `str`.
    * Les valeurs de ce dictionnaire sont de type `float`.

#### `Optional`

    This defines the name of the query parameter that should be provided in the request
    with the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the query parameter automatically and provides it as the
    dependency result. But it doesn't define how to send that API key to the client.

    ## Usage

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

!!! info

        os.remove(log)  # pragma: no cover
    response = client.post("/send-notification/******@****.***")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Notification sent in the background"}
    with open("./log.txt") as f:

async def send_notification(
    email: str, background_tasks: BackgroundTasks, q: str = Depends(get_query)
):
    message = f"message to {email}\n"
    background_tasks.add_task(write_log, message)

    assert response.status_code == 200, response.text
    assert response.json() == {"message": "No file sent"}


@needs_py310
def test_post_uploadfile_no_body(client: TestClient):
    response = client.post("/uploadfile/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "No upload file sent"}


@needs_py310
def test_post_file(tmp_path: Path, client: TestClient):

     Cela aide beaucoup pendant le **développement**, mais vous **ne devriez pas** l'utiliser en **production**.

## Hypercorn avec Trio

Starlette et **FastAPI** sont basés sur
<a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>, qui les rend

        return {"message": "Notification sent in the background"}
    ```
    """

    def add_task(
        self,
        func: Annotated[
            Callable[P, Any],
            Doc(
                """
                The function to call after the response is sent.

                It can be a regular `def` function or an `async def` function.
                """

So, the user will also have a `password` when creating it.

But for security, the `password` won't be in other Pydantic *models*, for example, it won't be sent from the API when reading a user.

=== "Python 3.10+"

    ```Python hl_lines="1  4-6  9-10  21-22  25-26"
    {!> ../../../docs_src/sql_databases/sql_app_py310/schemas.py!}
    ```

=== "Python 3.9+"