users_router = APIRouter()

        @users_router.get("/users/")
        def read_users():
            return [{"name": "Rick"}, {"name": "Morty"}]

        internal_router.include_router(users_router)
        app.include_router(internal_router)
        ```
        """
        if prefix:
            assert prefix.startswith("/"), "A path prefix must start with '/'"
            assert not prefix.endswith(

## 多次使用不同的 `prefix` 包含同一个路由器

你也可以在*同一*路由器上使用不同的前缀来多次使用 `.include_router()`。

在有些场景这可能有用，例如以不同的前缀公开同一个的 API，比方说 `/api/v1` 和 `/api/latest`。

这是一个你可能并不真正需要的高级用法，但万一你有需要了就能够用上。

## 在另一个 `APIRouter` 中包含一个 `APIRouter`

与在 `FastAPI` 应用程序中包含 `APIRouter` 的方式相同，你也可以在另一个 `APIRouter` 中包含 `APIRouter`，通过：

```Python
router.include_router(other_router)
```

Die ursprüngliche Abhängigkeit könnte in einer *Pfadoperation-Funktion*, einem *Pfadoperation-Dekorator* (wenn Sie den Rückgabewert nicht verwenden), einem `.include_router()`-Aufruf, usw. verwendet werden.

FastAPI kann sie in jedem Fall überschreiben.

///

这样一来，**FastAPI** 就会调用覆盖依赖项，不再调用原依赖项。

```Python hl_lines="26-27  30"
{!../../docs_src/dependency_testing/tutorial001.py!}
```

/// tip | "提示"

**FastAPI** 应用中的任何位置都可以实现覆盖依赖项。

原依赖项可用于*路径操作函数*、*路径操作装饰器*（不需要返回值时）、`.include_router()` 调用等。

FastAPI 可以覆盖这些位置的依赖项。

///

然后，使用 `app.dependency_overrides` 把覆盖依赖项重置为空**字典**：

```Python
app.dependency_overrides = {}
```

/// tip | "提示"

A dependência original pode estar sendo utilizada em uma *função de operação de rota*, um *docorador de operação de rota* (quando você não utiliza o valor retornado), uma chamada ao `.include_router()`, etc.

O FastAPI ainda poderá sobrescrevê-lo.

///

E então você pode redefinir as suas sobreposições (removê-las) definindo o `app.dependency_overrides` como um `dict` vazio:

```Python

    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"},

@router.get("/router-decorator-depends/", dependencies=[Depends(common_parameters)])
async def router_decorator_depends():
    return {"in": "router-decorator-depends"}


app.include_router(router)

client = TestClient(app)


async def overrider_dependency_simple(q: Optional[str] = None):
    return {"q": q, "skip": 5, "limit": 10}


async def overrider_sub_dependency(k: str):

        ```python
        from fastapi import FastAPI

        from .users import users_router

        app = FastAPI()

        app.include_router(users_router)
        ```
        """
        self.router.include_router(
            router,
            prefix=prefix,
            tags=tags,
            dependencies=dependencies,
            responses=responses,

That means that, for example, to apply authentication to all the *path operations* in a router it would end up being done in a different file, instead of keeping related logic together.