# Klassen als Abhängigkeiten { #classes-as-dependencies }

Bevor wir tiefer in das **Dependency Injection** System eintauchen, lassen Sie uns das vorherige Beispiel verbessern.

## Ein `dict` aus dem vorherigen Beispiel { #a-dict-from-the-previous-example }

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.

If you pass a "callable" as a dependency in **FastAPI**, it will analyze the parameters for that "callable", and process them in the same way as the parameters for a *path operation function*. Including sub-dependencies.

# Classes como Dependências { #classes-as-dependencies }

Antes de nos aprofundarmos no sistema de **Injeção de Dependência**, vamos melhorar o exemplo anterior.

## `dict` do exemplo anterior { #a-dict-from-the-previous-example }

No exemplo anterior, nós retornávamos um `dict` da nossa dependência ("injetável"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

# Классы как зависимости { #classes-as-dependencies }

Прежде чем углубиться в систему **Внедрения Зависимостей**, давайте обновим предыдущий пример.

## `dict` из предыдущего примера { #a-dict-from-the-previous-example }

В предыдущем примере мы возвращали `dict` из нашей зависимости:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

Но затем мы получаем `dict` в параметре `commons` *функции-обработчика пути*.

# Clases como dependencias { #classes-as-dependencies }

Antes de profundizar en el sistema de **Inyección de Dependencias**, vamos a mejorar el ejemplo anterior.

## Un `dict` del ejemplo anterior { #a-dict-from-the-previous-example }

En el ejemplo anterior, estábamos devolviendo un `dict` de nuestra dependencia ("dependable"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

In this case, you would accept any `dict` as long as it has `int` keys with `float` values:

{* ../../docs_src/body_nested_models/tutorial009_py39.py hl[7] *}

/// tip

Keep in mind that JSON only supports `str` as keys.

But Pydantic has automatic data conversion.

* operation IDs: IDs de operação
* path (as in URL path): path
* path operation: operação de rota
* path operation function: função de operação de rota
* prefix: prefixo
* request (as in HTTP request): request (do not change if it's already translated to requisição)
* router (as in FastAPI's router): router (do not change if it's already translated to "roteador" or "roteadores")

        while (authElements.hasMoreElements()) {
            ASN1Sequence authElement = ASN1Util.as(ASN1Sequence.class, authElements);
            ASN1Integer authType = ASN1Util.as(ASN1Integer.class, ASN1Util.as(ASN1TaggedObject.class, authElement, 0));
            DEROctetString authData = ASN1Util.as(DEROctetString.class, ASN1Util.as(ASN1TaggedObject.class, authElement, 1));

The same as we were doing before in the *path operation* directly, our new dependency `get_current_user` will receive a `token` as a `str` from the sub-dependency `oauth2_scheme`:

{* ../../docs_src/security/tutorial002_an_py310.py hl[25] *}

## Get the user { #get-the-user }

`get_current_user` will use a (fake) utility function we created, that takes a token as a `str` and returns our Pydantic `User` model:

* Todas elas incluirão as `responses` predefinidas.
* Todas essas *operações de rota* terão a lista de `dependencies` avaliada/executada antes delas.
    * Se você também declarar dependências em uma *operação de rota* específica, **elas também serão executadas**.