#### `lru_cache` Technical Details

    ```Python hl_lines="1  10"
    {!> ../../../docs_src/settings/app03/main.py!}
    ```

Dann wird bei allen nachfolgenden Aufrufen von `get_settings()`, in den Abhängigkeiten für darauffolgende Requests, dasselbe Objekt zurückgegeben, das beim ersten Aufruf zurückgegeben wurde, anstatt den Code von `get_settings()` erneut auszuführen und ein neues `Settings`-Objekt zu erstellen.

#### Technische Details zu `lru_cache`

    ```Python hl_lines="1  11"
    {!> ../../../docs_src/settings/app03_an/main.py!}
    ```

=== "Python 3.8+ 非注解版本"

    !!! tip
        如果可能，请尽量使用 `Annotated` 版本。

    ```Python hl_lines="1  10"
    {!> ../../../docs_src/settings/app03/main.py!}
    ```

然后，在下一次请求的依赖项中对 `get_settings()` 进行任何后续调用时，它不会执行 `get_settings()` 的内部代码并创建新的 `Settings` 对象，而是返回在第一次调用时返回的相同对象，一次又一次。

#### `lru_cache` 技术细节

{!../../../docs_src/settings/app02/main.py!}
```

!!! tip
    👥 🔜 🔬 `@lru_cache` 🍖.

    🔜 👆 💪 🤔 `get_settings()` 😐 🔢.

& ⤴️ 👥 💪 🚚 ⚫️ ⚪️➡️ *➡ 🛠️ 🔢* 🔗 & ⚙️ ⚫️ 🙆 👥 💪 ⚫️.

```Python hl_lines="16  18-20"
{!../../../docs_src/settings/app02/main.py!}
```

### ⚒ & 🔬

⤴️ ⚫️ 🔜 📶 ⏩ 🚚 🎏 ⚒ 🎚 ⏮️ 🔬 🏗 🔗 🔐 `get_settings`:

```Python hl_lines="9-10  13  21"

    assertThat(frameLog(false, 3, 100, TYPE_HEADERS, FLAG_END_HEADERS))
      .isEqualTo(">> 0x00000003   100 HEADERS       END_HEADERS")
    assertThat(frameLog(false, 3, 0, TYPE_DATA, FLAG_END_STREAM))
      .isEqualTo(">> 0x00000003     0 DATA          END_STREAM")
    assertThat(frameLog(true, 0, 15, TYPE_SETTINGS, FLAG_NONE))
      .isEqualTo("<< 0x00000000    15 SETTINGS      ")
    assertThat(frameLog(false, 0, 0, TYPE_SETTINGS, FLAG_ACK))

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: Annotated[config.Settings, Depends(get_settings)]):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

@needs_pydanticv2
def test_settings(monkeypatch: MonkeyPatch):
    from docs_src.settings.app02 import main

    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    settings = main.get_settings()
    assert settings.app_name == "Awesome API"
    assert settings.items_per_user == 50


@needs_pydanticv2
def test_override_settings():
    from docs_src.settings.app02 import test_main

from typing_extensions import Annotated

from .config import Settings

app = FastAPI()


@lru_cache
def get_settings():
    return Settings()


@app.get("/info")
async def info(settings: Annotated[Settings, Depends(get_settings)]):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: Annotated[config.Settings, Depends(get_settings)]):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: config.Settings = Depends(get_settings)):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,