)
router_b_override.include_router(router_b_a, prefix="/a")
router_a.include_router(router_a_a, prefix="/a")
router_a.include_router(
    router_a_b_override, prefix="/b", default_response_class=PlainTextResponse
)
app.include_router(router_a, prefix="/a")
app.include_router(
    router_b_override, prefix="/b", default_response_class=PlainTextResponse
)


client = TestClient(app)

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


@router.get("/users/{id}")
def read_user(segment: str, id: str):
    return {"segment": segment, "id": id}


app.include_router(router, prefix="/{segment}")


client = TestClient(app)


def test_get():
    response = client.get("/seg/users/foo")

    callbacks=callback_router3.routes,
)

router2_override.include_router(router4_override)

router2_override.include_router(router4_default)

router2_default.include_router(
    router4_override,
    prefix="/level3",
    tags=["level3a", "level3b"],
    dependencies=[Depends(dep3)],
    responses={
        403: {"description": "Client error level 3"},
        503: {"description": "Server error level 3"},

    color: var(--color-text);
    /* font-size: 18px; */
    font-size: 15px;
    /* font-family: 'Fira Mono', Consolas, Menlo, Monaco, 'Courier New', Courier, monospace; */
    font-family: 'Roboto Mono', 'Fira Mono', Consolas, Menlo, Monaco, 'Courier New', Courier, monospace;
    border-radius: 4px;
    padding: 75px 45px 35px;
    position: relative;
    -webkit-box-sizing: border-box;
            box-sizing: border-box;

from ..dependencies import get_token_header

router = APIRouter(
    prefix="/items",
    tags=["items"],
    dependencies=[Depends(get_token_header)],
    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):

from .internal import admin
from .routers import items, users

app = FastAPI(dependencies=[Depends(get_query_token)])


app.include_router(users.router)
app.include_router(items.router)
app.include_router(
    admin.router,
    prefix="/admin",
    tags=["admin"],
    dependencies=[Depends(get_token_header)],
    responses={418: {"description": "I'm a teapot"}},
)


@app.get("/")

Wir importieren das Submodul `items` direkt, anstatt nur seine Variable `router` zu importieren.

Das liegt daran, dass wir im Submodul `users` auch eine weitere Variable namens `router` haben.

Wenn wir eine nach der anderen importiert hätten, etwa:

```Python
from .routers.items import router
from .routers.users import router
```

```Python hl_lines="35"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip
    Notice that you are not passing the router itself (`invoices_callback_router`) to `callback=`, but the attribute `.routes`, as in `invoices_callback_router.routes`.

### Check the docs

)
router_b_override.include_router(router_b_a, prefix="/a")
router_a.include_router(router_a_a, prefix="/a")
router_a.include_router(
    router_a_b_override, prefix="/b", default_response_class=PlainTextResponse
)
app.include_router(router_a, prefix="/a")
app.include_router(
    router_b_override, prefix="/b", default_response_class=PlainTextResponse
)


client = TestClient(app)

from ..dependencies import get_token_header

router = APIRouter(
    prefix="/items",
    tags=["items"],
    dependencies=[Depends(get_token_header)],
    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):