The OAuth2 spec says it is required and MUST be the fixed string
                "password". Nevertheless, this dependency class is permissive and
                allows not passing it. If you want to enforce it, use instead the
                `OAuth2PasswordRequestFormStrict` dependency.
                """
            ),
        ] = None,
        username: Annotated[
            str,
            Form(),

And the more exotic ones:

* `@app.options()`
* `@app.head()`
* `@app.patch()`
* `@app.trace()`

!!! tip
    You are free to use each operation (HTTP method) as you wish.

    **FastAPI** doesn't enforce any specific meaning.

    The information here is presented as a guideline, not a requirement.

    For example, when using GraphQL you normally perform all the actions using only `POST` operations.

* An optional `grant_type`.

!!! tip
    The OAuth2 spec actually *requires* a field `grant_type` with a fixed value of `password`, but `OAuth2PasswordRequestForm` doesn't enforce it.

    If you need to enforce it, use `OAuth2PasswordRequestFormStrict` instead of `OAuth2PasswordRequestForm`.

* An optional `client_id` (we don't need it for our example).
* An optional `client_secret` (we don't need it for our example).

De nombreux développeurs et équipes dépendent déjà de **FastAPI** pour leurs projets (y compris moi et mon équipe).

Mais il y a encore de nombreuses améliorations et fonctionnalités à venir.

**FastAPI** a un grand avenir devant lui.

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps

```Python
burgers = await get_burgers(2)
```

    The `Union` in `Union[str, None]` will allow your editor to give you better support and detect errors.

## Additional validation

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated`

To achieve that, first import:

* `Query` from `fastapi`

Containers are mainly a tool to simplify the process of **building and deploying** an application, but they don't enforce a particular approach to handle these **deployment concepts**, and there are several possible strategies.

The **good news** is that with each different strategy there's a way to cover all of the deployment concepts. 🎉

    * **WebSockets**
    * de tester le code très facilement avec `requests` et `pytest`
    * **<abbr title="Cross-Origin Resource Sharing">CORS</abbr>**
    * **Cookie Sessions**
    * ... et plus encore.

## Performance

                ```python
                app = FastAPI(
                    contact={
                        "name": "Deadpoolio the Amazing",
                        "url": "http://x-force.example.com/contact/",
                        "email": "dp@x-force.example.com",
                    }
                )
                ```
                """
            ),
        ] = None,
        license_info: Annotated[