# Paramètres d'en-tête { #header-parameters }

Vous pouvez définir des paramètres `Header` de la même manière que vous définissez des paramètres `Query`, `Path` et `Cookie`.

## Importer `Header` { #import-header }

Commencez par importer `Header` :

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Déclarer des paramètres `Header` { #declare-header-parameters }

* et en importer le sous-module `items` (le fichier `app/routers/items.py`) et `users` (le fichier `app/routers/users.py`)...

Le module `items` aura une variable `router` (`items.router`). C'est celle que nous avons créée dans le fichier `app/routers/items.py`, c'est un objet `APIRouter`.

Nous faisons ensuite la même chose pour le module `users`.

Nous pourrions aussi les importer ainsi :

```Python

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_updates.{request.param}")

    client = TestClient(mod.app)

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_multiple_params.{request.param}")

    client = TestClient(mod.app)

import importlib

import pytest
from dirty_equals import IsList
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial005_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_nested_models.{request.param}")

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial004_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body.{request.param}")

    client = TestClient(mod.app)

Asegúrate de crear un [entorno virtual](../virtual-environments.md), activarlo, y luego instalarlo, por ejemplo:

```console
$ pip install python-multipart
```

///

## Importar `Form` { #import-form }

Importar `Form` desde `fastapi`:

{* ../../docs_src/request_forms/tutorial001_an_py310.py hl[3] *}

## Definir parámetros de `Form` { #define-form-parameters }

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial001_py310", marks=needs_py310),
        pytest.param("tutorial001_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_updates.{request.param}")

    client = TestClient(mod.app)

import importlib

import pytest
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial005_py310", marks=needs_py310),
        pytest.param("tutorial005_an_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):