SkipTLSVerify:         viper.GetBool(constants.SkipTLSVerify),
		K8sServiceProtocol:    os.Getenv("KUBERNETES_SERVICE_PROTOCOL"),
		K8sServiceHost:        os.Getenv("KUBERNETES_SERVICE_HOST"),
		K8sServicePort:        os.Getenv("KUBERNETES_SERVICE_PORT"),
		K8sNodeName:           os.Getenv("KUBERNETES_NODE_NAME"),
		K8sServiceAccountPath: constants.ServiceAccountPath,

		CNIBinSourceDir:  constants.CNIBinDir,

Например, у вас есть файл `main.py`:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

Второй аргумент <a href=«https://docs.python.org/3.8/library/os.html#os.getenv» class=«external-link» target=«_blank»>`os.getenv()`</a> - это возвращаемое по умолчанию значение.

Sie könnten zum Beispiel eine Datei `main.py` haben mit:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | "Tipp"

Das zweite Argument für <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> ist der zurückzugebende Defaultwert.

        }
        if (generatorList != null && !generatorList.isEmpty()) {
            String path = System.getenv("PATH");
            if (path == null) {
                path = System.getenv("Path");
            }
            if (path == null) {
                path = System.getenv("path");
            }
            final List<String> pathList = new ArrayList<>();
            pathList.add("/usr/share/fess/bin");

🖼 👆 💪 ✔️ 📁 `main.py` ⏮️:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

🥈 ❌ <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 🔢 💲 📨.

🚥 🚫 🚚, ⚫️ `None` 🔢, 📥 👥 🚚 `"World"` 🔢 💲 ⚙️.

///

⤴️ 👆 💪 🤙 👈 🐍 📋:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// dica

O segundo parâmetro em <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> é o valor padrão para o retorno.

这种做法相当常见，有一个名称，这些环境变量通常放在一个名为 `.env` 的文件中，该文件被称为“dotenv”。

/// tip

以点 (`.`) 开头的文件是 Unix-like 系统（如 Linux 和 macOS）中的隐藏文件。

但是，dotenv 文件实际上不一定要具有确切的文件名。

///

Pydantic 支持使用外部库从这些类型的文件中读取。您可以在<a href="https://docs.pydantic.dev/latest/concepts/pydantic_settings/#dotenv-env-support" class="external-link" target="_blank">Pydantic 设置: Dotenv (.env) 支持</a>中阅读更多相关信息。

/// tip

	"istio.io/istio/pkg/test/env"
	"istio.io/istio/pkg/test/util/retry"
)

const (
	cniConfSubDir    = "/testdata/pre/"
	k8sSvcAcctSubDir = "/testdata/k8s_svcacct/"

	defaultFileMode = 0o644
)

func getEnv(key, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	return fallback
}

func mktemp(dir, prefix string, t *testing.T) string {
	t.Helper()

	//
	// Until the container image changes, this behavior has to be preserved.
	if isPresent(EnvKMSSecretKey) && os.Getenv(EnvKMSSecretKey) == "" {
		os.Unsetenv(EnvKMSSecretKey)
	}
	if isPresent(EnvKMSSecretKeyFile) {
		if filename := os.Getenv(EnvKMSSecretKeyFile); filename == "" {
			os.Unsetenv(EnvKMSSecretKeyFile)
		} else if _, err := os.Stat(filename); errors.Is(err, os.ErrNotExist) {

		fmt.Fprintf(os.Stderr, "adb %s\n%s", strings.Join(args, " "), out)
		return err
	}
	return nil
}

func adbCmd(args ...string) *exec.Cmd {
	if flags := os.Getenv("GOANDROID_ADB_FLAGS"); flags != "" {
		args = append(strings.Split(flags, " "), args...)
	}
	return exec.Command("adb", args...)
}

const (
	deviceRoot   = "/data/local/tmp/go_android_exec"