{* ../../docs_src/settings/app02_an_py39/config.py hl[10] *}

Nota que ahora no creamos una instance por defecto `settings = Settings()`.

### El archivo principal de la app { #the-main-app-file }

Ahora creamos una dependencia que devuelve un nuevo `config.Settings()`.

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip | Consejo

{* ../../docs_src/settings/app02_an_py39/config.py hl[10] *}

Perceba que agora não criamos uma instância padrão `settings = Settings()`.

### O arquivo principal da aplicação { #the-main-app-file }

Agora criamos uma dependência que retorna um novo `config.Settings()`.

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip | Dica

{* ../../docs_src/settings/app02_an_py39/config.py hl[10] *}

Notice that now we don't create a default instance `settings = Settings()`.

### The main app file { #the-main-app-file }

Now we create a dependency that returns a new `config.Settings()`.

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip

We'll discuss the `@lru_cache` in a bit.

import importlib
from types import ModuleType

import pytest
from pytest import MonkeyPatch


@pytest.fixture(
    name="mod_path",
    params=[
        pytest.param("app02_py39"),
        pytest.param("app02_an_py39"),
    ],
)
def get_mod_path(request: pytest.FixtureRequest):
    mod_path = f"docs_src.settings.{request.param}"
    return mod_path


@pytest.fixture(name="main_mod")

### 主应用程序文件

现在我们创建一个依赖项，返回一个新的 `config.Settings()`。

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip

我们稍后会讨论 `@lru_cache`。

目前，您可以将 `get_settings()` 视为普通函数。

///

然后，我们可以将其作为依赖项从“路径操作函数”中引入，并在需要时使用它。

{* ../../docs_src/settings/app02_an_py39/main.py hl[17,19:21] *}

### 设置和测试

然后，在测试期间，通过创建 `get_settings` 的依赖项覆盖，很容易提供一个不同的设置对象：

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[1,3] title["app/routers/users.py"] *}

### *Pfadoperationen* mit `APIRouter` { #path-operations-with-apirouter }

Und dann verwenden Sie ihn, um Ihre *Pfadoperationen* zu deklarieren.

Verwenden Sie ihn auf die gleiche Weise wie die Klasse `FastAPI`:

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[6,11,16] title["app/routers/users.py"] *}

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[1,3] title["app/routers/users.py"] *}

### Создание *эндпоинтов* с помощью `APIRouter` { #path-operations-with-apirouter }

В дальнейшем используйте `APIRouter` для объявления *эндпоинтов*, точно также, как вы используете класс `FastAPI`:

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[6,11,16] title["app/routers/users.py"] *}

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[1,3] title["app/routers/users.py"] *}

### *Path operations* con `APIRouter` { #path-operations-with-apirouter }

Y luego lo usas para declarar tus *path operations*.

Úsalo de la misma manera que usarías la clase `FastAPI`:

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[6,11,16] title["app/routers/users.py"] *}

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[1,3] title["app/routers/users.py"] *}

### *Operações de Rota* com `APIRouter` { #path-operations-with-apirouter }

E então você o utiliza para declarar suas *operações de rota*.

Utilize-o da mesma maneira que utilizaria a classe  `FastAPI`:

{* ../../docs_src/bigger_applications/app_an_py39/routers/users.py hl[6,11,16] title["app/routers/users.py"] *}

import pytest
from fastapi.testclient import TestClient
from pytest import MonkeyPatch


@pytest.fixture(
    name="mod_path",
    params=[
        pytest.param("app03_py39"),
        pytest.param("app03_an_py39"),
    ],
)
def get_mod_path(request: pytest.FixtureRequest):
    mod_path = f"docs_src.settings.{request.param}"
    return mod_path


@pytest.fixture(name="main_mod")