/// tip

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="19-21"
{!> ../../docs_src/body_multiple_params/tutorial001.py!}
```

////

/// note

Notice that, in this case, the `item` that would be taken from the body is optional. As it has a `None` default value.

///

## Multiple body parameters

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="4"
{!> ../../docs_src/body_fields/tutorial001.py!}
```

////

/// warning

Notice that `Field` is imported directly from `pydantic`, not from `fastapi` as are all the rest (`Query`, `Path`, `Body`, etc).

///

## Declare model attributes

You can then use `Field` with model attributes:

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* etc.

```Python hl_lines="6"
{!../../docs_src/response_status_code/tutorial001.py!}
```

/// note

Notice that `status_code` is a parameter of the "decorator" method (`get`, `post`, etc). Not of your *path operation function*, like all the parameters and body.

///

# Path Operation Configuration

There are several parameters that you can pass to your *path operation decorator* to configure it.

/// warning

Notice that these parameters are passed directly to the *path operation decorator*, not to your *path operation function*.

///

## Response Status Code

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

Vous la mettez au dessus d'une fonction. Comme un joli chapeau décoratif (j'imagine que ce terme vient de là 🤷🏻‍♂).

Un "décorateur" prend la fonction en dessous et en fait quelque chose.

Dans notre cas, ce décorateur dit à **FastAPI** que la fonction en dessous correspond au **chemin** `/` avec l'**opération** `get`.

C'est le "**décorateur d'opération de chemin**".

///

```Python hl_lines="19-24  28"
{!../../docs_src/additional_responses/tutorial002.py!}
```

/// note

Notice that you have to return the image using a `FileResponse` directly.

///

/// info

```Python hl_lines="2  12  15-18"
{!../../docs_src/app_testing/tutorial001.py!}
```

/// tip

Notice that the testing functions are normal `def`, not `async def`.

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

/// note | "Technical Details"

You could also use `from starlette.testclient import TestClient`.

<img src="/img/tutorial/security/image10.png">

/// note

Notice the header `Authorization`, with a value that starts with `Bearer `.

///

## Advanced usage with `scopes`

OAuth2 has the notion of "scopes".

```

////

/// tip

You can actually use this same technique with an HTTP `PUT` operation.

But the example here uses `PATCH` because it was created for these use cases.

///

/// note

Notice that the input model is still validated.

So, if you want to receive partial updates that can omit all the attributes, you need to have a model with all the attributes marked as optional (with default values or `None`).

```

////

//// tab | Python 3.8+

```Python hl_lines="10"
{!> ../../docs_src/query_params_str_validations/tutorial002_an.py!}
```

////

Notice that the default value is still `None`, so the parameter is still optional.