Isso é bastante simples (e não muito útil), mas irá nos ajudar a focar em como as subdependências funcionam.

## Segunda dependência, "injetável" e "dependente"

Então, você pode criar uma outra função para uma dependência (um "injetável") que ao mesmo tempo declara sua própria dependência (o que faz dela um "dependente" também):

//// tab | Python 3.10+

```Python hl_lines="13"
{!> ../../docs_src/dependencies/tutorial005_an_py310.py!}
```

/// tip | "Dica"

Utilize a versão com `Annotated` se possível.

///

```Python hl_lines="3"
{!> ../../docs_src/dependencies/tutorial001.py!}
```

////

### Declarando a dependência, no "dependente"

Da mesma forma que você utiliza `Body`, `Query`, etc. Como parâmetros de sua *função de operação de rota*, utilize `Depends` com um novo parâmetro:

//// tab | Python 3.10+

```Python hl_lines="13  18"

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant"

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

//// tab | Python 3.10+

```Python hl_lines="13"
{!> ../../docs_src/dependencies/tutorial005_an_py310.py!}
```

## Zweite Abhängigkeit, „Dependable“ und „Dependant“

Dann können Sie eine weitere Abhängigkeitsfunktion (ein „Dependable“) erstellen, die gleichzeitig eine eigene Abhängigkeit deklariert (also auch ein „Dependant“ ist):

//// tab | Python 3.10+

```Python hl_lines="13"
{!> ../../docs_src/dependencies/tutorial005_an_py310.py!}
```

////

) -> Dependant:
    if visited is None:
        visited = []
    visited.append(dependant.cache_key)

    flat_dependant = Dependant(
        path_params=dependant.path_params.copy(),
        query_params=dependant.query_params.copy(),
        header_params=dependant.header_params.copy(),
        cookie_params=dependant.cookie_params.copy(),
        body_params=dependant.body_params.copy(),

    * Required scopes `["items"]` with the dependency:
    * `get_current_active_user`:
        *  The dependency function `get_current_active_user` has:
            * Required scopes `["me"]` with the dependency:
            * `get_current_user`:
                * The dependency function `get_current_user` has:
                    * No scopes required by itself.
                    * A dependency using `oauth2_scheme`.

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection"

Es ist so konzipiert, sehr einfach zu verwenden zu sein und es jedem Entwickler sehr leicht zu machen, andere Komponenten mit **FastAPI** zu integrieren.

## Was ist „Dependency Injection“

Ele sempre terá os escopos de segurança declarados nas dependências atuais de `Security` e todos os dependentes para **aquela** *operação de rota* **específica** e **aquela** árvore de dependência **específica**.

There are some scenarios where you might want to override a dependency during testing.

You don't want the original dependency to run (nor any of the sub-dependencies it might have).

Instead, you want to provide a different dependency that will be used only during tests (possibly only some specific tests), and will provide a value that can be used where the value of the original dependency was used.

### Use cases: external service