# new_section = Section(title=new_title, children=new_children)
            item.title = new_title
            item.children = new_children
            new_items.append(item)
        else:
            new_items.append(item)
    return new_items


def on_nav(
    nav: Navigation, *, config: MkDocsConfig, files: Files, **kwargs: Any
) -> Navigation:

So, the section:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

will run.

---

This won't happen if you import that module (file).

So, if you have another file `importer.py` with:

```Python
from myapp import app

# Some more code
```

            return encoder(obj)

    try:
        data = dict(obj)
    except Exception as e:
        errors: List[Exception] = []
        errors.append(e)
        try:
            data = vars(obj)
        except Exception as e:
            errors.append(e)
            raise ValueError(errors) from e
    return jsonable_encoder(
        data,
        include=include,
        exclude=exclude,

# Background Tasks

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

<img src="/img/tutorial/body/image02.png">

## Editor support

In your editor, inside your function you will get type hints and completion everywhere (this wouldn't happen if you received a `dict` instead of a Pydantic model):

<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

<img src="/img/tutorial/body/image04.png">

Pour ces cas, vous pouvez spécifier un appel à `jsonable_encoder` pour convertir vos données avant de les passer à une réponse :

```Python hl_lines="6-7  21-22"
{!../../../docs_src/response_directly/tutorial001.py!}
```

!!! note "Détails techniques"

* <a href="https://github.com/tiangolo/fastapi/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3Aquestion+-label%3Aanswered+" class="external-link" target="_blank">GitHub-Issues</a>

In vielen Fällen kennen Sie möglicherweise bereits die Antwort auf diese Fragen. 🤓

                ).errors()
                use_errors.extend(new_errors)
            elif isinstance(error, list):
                use_errors.extend(_normalize_errors(error))
            else:
                use_errors.append(error)
        return use_errors

    def _model_rebuild(model: Type[BaseModel]) -> None:
        model.update_forward_refs()

    def _model_dump(

                field.validate, response_content, {}, loc=("response",)
            )
        if isinstance(errors_, list):
            errors.extend(errors_)
        elif errors_:
            errors.append(errors_)
        if errors:
            raise ResponseValidationError(
                errors=_normalize_errors(errors), body=response_content
            )

        if hasattr(field, "serialize"):