@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

🚥 🔗 🔢 💖:

```Python
def get_settings():
    return Settings()
```

👥 🔜 ✍ 👈 🎚 🔠 📨, & 👥 🔜 👂 `.env` 📁 🔠 📨. 👶 👶

✋️ 👥 ⚙️ `@lru_cache` 👨‍🎨 🔛 🔝, `Settings` 🎚 🔜 ✍ 🕴 🕐, 🥇 🕰 ⚫️ 🤙. 👶 👶

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

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

Then for any subsequent calls of `get_settings()` in the dependencies for the next requests, instead of executing the internal code of `get_settings()` and creating a new `Settings` object, it will return the same object that was returned on the first call, again and again.

#### `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`

        SettingsState state = findSettingsAndLoadIfAppropriate(gradle, startParameter, settingsLocation, gradle.getClassLoaderScope());
        SettingsInternal settings = state.getSettings();
        ProjectSpec spec = ProjectSpecs.forStartParameter(startParameter, settings);
        if (useEmptySettings(spec, settings, startParameter)) {
            // Discard the loaded settings and replace with an empty one

import java.io.File;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertNotNull;

/**
 */
class DefaultSettingsBuilderFactoryTest {

    private File getSettings(String name) {
        return new File("src/test/resources/settings/factory/" + name + ".xml").getAbsoluteFile();
    }

    @Test
    void testCompleteWiring() throws Exception {

    }

    @Override
    public void prepareProjects(GradleInternal gradle) {
        // Setup classloader for root project, all other projects will be derived from this.
        SettingsInternal settings = gradle.getSettings();
        ClassLoaderScope settingsClassLoaderScope = settings.getClassLoaderScope();
        ClassLoaderScope buildSrcClassLoaderScope = settingsClassLoaderScope.createChild("buildSrc[" + gradle.getIdentityPath() + "]", null);

            }
            final HttpServletResponse response = LaResponseUtil.getResponse();
            try {
                final Auth auth = new Auth(getSettings(), request, response);
                final Saml2Settings settings = auth.getSettings();
                settings.setSPValidationOnly(true);
                final String metadata = settings.getSPMetadata();

        return SystemProperties.getInstance().withSystemProperties(() -> Ivy.newInstance(new IvySettings()));
    }

    private void releaseIvy(Ivy ivy) {
        // cleanup
        ivy.getSettings().getResolvers().clear();
        ivy.getSettings().setDefaultResolver(null);

        lock.lock();
        try {
            if (cached.size() < MAX_CACHED_IVY_INSTANCES) {
                cached.add(ivy);
            }

=== "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

`@lru_cache` 修改了它所装饰的函数，以返回第一次返回的相同值，而不是再次计算它，每次都执行函数的代码。

因此，下面的函数将对每个参数组合执行一次。然后，每个参数组合返回的值将在使用完全相同的参数组合调用函数时再次使用。