include_in_schema: bool = True,
        json_schema_extra: Union[Dict[str, Any], None] = None,
        **extra: Any,
    ):
        if example is not _Unset:
            warnings.warn(
                "`example` has been deprecated, please use `examples` instead",
                category=DeprecationWarning,
                stacklevel=4,
            )
        self.example = example
        self.include_in_schema = include_in_schema

# Using Dataclasses

FastAPI is built on top of **Pydantic**, and I have been showing you how to use Pydantic models to declare requests and responses.

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

```Python hl_lines="1  7-12  19-20"
{!../../../docs_src/dataclasses/tutorial001.py!}
```

What inspired **FastAPI**, how it compares to alternatives and what it learned from them.

## Intro

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

I have been avoiding the creation of a new framework for several years. First I tried to solve all the features covered by **FastAPI** using many different frameworks, plug-ins, and tools.

* Review Pull Requests, [especially important for translations](contributing.md#translations){.internal-link target=_blank}.

A round of applause to them. 👏 🙇

## FastAPI Experts

These are the users that have been [helping others the most with questions in GitHub](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank}. 🙇

They have proven to be **FastAPI Experts** by helping many others. ✨

!!! tip

<blockquote markdown="1">

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

I have been avoiding the creation of a new framework for several years. First I tried to solve all the features covered by **FastAPI** using many different frameworks, plug-ins, and tools.

So, to avoid ID collisions, when creating the JWT token for the user, you could prefix the value of the `sub` key, e.g. with `username:`. So, in this example, the value of `sub` could have been: `username:johndoe`.

The important thing to keep in mind is that the `sub` key should have a unique identifier across the entire application, and it should be a string.

## Check it

You can use simple tools like `htop` to see the CPU and RAM used in your server or the amount used by each process. Or you can use more complex monitoring tools, which may be distributed across servers, etc.

## Recap

You have been reading here some of the main concepts that you would probably need to keep in mind when deciding how to deploy your application:

* Security - HTTPS
* Running on startup
* Restarts

{!../../../docs_src/query_params_str_validations/tutorial001.py!}
```

Le paramètre de requête `q` a pour type `Union[str, None]` (ou `str | None` en Python 3.10), signifiant qu'il est de type `str` mais pourrait aussi être égal à `None`, et bien sûr, la valeur par défaut est `None`, donc **FastAPI** saura qu'il n'est pas requis.

!!! note
    **FastAPI** saura que la valeur de `q` n'est pas requise grâce à la valeur par défaut `= None`.

!!! info
    À nouveau, en utilisant uniquement les déclarations de type Python, **FastAPI** vous fournit automatiquement une documentation interactive (via Swagger UI).

    On voit bien dans la documentation que `item_id` est déclaré comme entier.

## Les avantages d'avoir une documentation basée sur une norme, et la documentation alternative.

cloud** qui fait une partie du travail pour vous, ou encore d'autres options possibles.

Je vais vous montrer certains des principaux concepts que vous devriez probablement avoir à l'esprit lors du déploiement
d'une application **FastAPI** (bien que la plupart de ces concepts s'appliquent à tout autre type d'application web).