## 參數化的相依 { #parameterized-dependencies }

到目前為止看到的相依都是固定的函式或類別。

但有些情況下，你可能想要能為相依設定參數，而不必宣告許多不同的函式或類別。

想像我們想要一個相依，用來檢查查詢參數 `q` 是否包含某些固定內容。

同時我們希望能將那個固定內容參數化。

## 「callable」的實例 { #a-callable-instance }

在 Python 中有一種方式可以讓一個類別的實例變成「callable」。

不是類別本身（類別本來就可呼叫），而是該類別的實例。

要做到這點，我們宣告一個 `__call__` 方法：

{* ../../docs_src/dependencies/tutorial011_an_py310.py hl[12] *}

FastAPI kann sie in jedem Fall überschreiben.

///

Anschließend können Sie Ihre Überschreibungen zurücksetzen (entfernen), indem Sie `app.dependency_overrides` auf ein leeres `dict` setzen:

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


/// tip | Tipp

To optimize performance when returning JSON data, use a return type or response model, that way Pydantic will handle the serialization to JSON on the Rust side, without going through Python. Read more in the docs for [Tutorial - Response Model - Return Type](../tutorial/response-model.md).

## Documentation Tags - OpenAPI { #documentation-tags-openapi }

O FastAPI ainda poderá sobrescrevê-la.

///

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

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


/// tip | Dica

    strategy:
      fail-fast: false
      matrix:
        # Override automatic language detection by changing the below list
        # Supported options are ['csharp', 'cpp', 'go', 'java', 'javascript', 'python']
        language: ['java', 'javascript']
        # Learn more...
        # https://docs.github.com/en/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#overriding-automatic-language-detection

En el HTML que contiene:

{% raw %}

```jinja
Item ID: {{ id }}
```

{% endraw %}

...mostrará el `id` tomado del `dict` de "contexto" que pasaste:

```Python
{"id": id}
```

Por ejemplo, con un ID de `42`, esto se renderizaría como:

```html
Item ID: 42
```

### Argumentos de la Plantilla `url_for` { #template-url-for-arguments }

`PUT`, mevcut verinin yerine geçmesi gereken veriyi almak için kullanılır.

### Değiştirerek güncelleme uyarısı { #warning-about-replacing }

Bu, `bar` öğesini `PUT` ile, body içinde şu verilerle güncellemek isterseniz:

```Python
{
    "name": "Barz",
    "price": 3,
    "description": None,
}
```

zaten kayıtlı olan `"tax": 20.2` alanını içermediği için, input model `"tax": 10.5` varsayılan değerini kullanacaktır.

# Benchmarks { #benchmarks }

Unabhängige TechEmpower-Benchmarks zeigen **FastAPI**-Anwendungen, die unter Uvicorn ausgeführt werden, als [eines der schnellsten verfügbaren Python-Frameworks](https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7), nur unterhalb von Starlette und Uvicorn selbst (die intern von FastAPI verwendet werden).

///

`status_code` parametresi, HTTP status code'u içeren bir sayı alır.

/// info | Bilgi

Alternatif olarak `status_code`, Python'un [`http.HTTPStatus`](https://docs.python.org/3/library/http.html#http.HTTPStatus)'ı gibi bir `IntEnum` da alabilir.

///

Bu sayede:

* Response'da o status code döner.
* OpenAPI şemasında (dolayısıyla kullanıcı arayüzlerinde de) bu şekilde dokümante edilir:

FastAPI побудовано поверх **Pydantic**, і я показував вам, як використовувати моделі Pydantic для оголошення запитів і відповідей.

Але FastAPI також підтримує використання [`dataclasses`](https://docs.python.org/3/library/dataclasses.html) таким самим чином:

{* ../../docs_src/dataclasses_/tutorial001_py310.py hl[1,6:11,18:19] *}