예를 들어 다음과 같은 `main.py` 파일이 있다고 합시다:

```Python hl_lines="3"
import os

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

/// tip | 팁

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 의 두 번째 인자는 반환할 기본값입니다.

여기서는 `"World"`를 넣었기에 기본값으로써 사용됩니다. 넣지 않으면 `None` 이 기본값으로 사용됩니다.

///

 * limitations under the License.
 */
package okhttp3

import okio.Buffer
import okio.Path
import okio.Path.Companion.toPath

val okHttpRoot: Path
  get() = getEnv("OKHTTP_ROOT")!!.toPath()

fun String(vararg codePoints: Int): String {
  val buffer = Buffer()
  for (codePoint in codePoints) {
    buffer.writeUtf8CodePoint(codePoint)
  }
  return buffer.readUtf8()

val platform = System.getProperty("okhttp.platform", "jdk9")
val testJavaVersion = System.getProperty("test.java.version", "21").toInt()

tasks.withType<Test> {
  useJUnitPlatform()
  onlyIf("By default not in CI") {
    System.getenv("CI") == null
      || (project.hasProperty("containerTests") && project.property("containerTests").toString().toBoolean())
  }

  jvmArgs(
    "-Dokhttp.platform=$platform",
  )

  if (platform == "loom") {

例如，你可以创建一个名为 `main.py` 的文件，其中包含以下内容：

```Python hl_lines="3"
import os

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

/// tip

第二个参数是 <a href="https://docs.python.org/zh-cn/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的默认返回值。

如果没有提供，默认值为 `None`，这里我们提供 `"World"` 作为默认值。

///

然后你可以调用这个 Python 程序：

/// tip | Совет

Чтобы это работало, вам нужно `pip install python-dotenv`.

///

### Файл `.env` { #the-env-file }

У вас может быть файл `.env` со следующим содержимым:

```bash
ADMIN_EMAIL="******@****.***"

Por exemplo, você poderia ter um arquivo `main.py` com:

```Python hl_lines="3"
import os

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

/// tip | Dica

O segundo argumento para <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 a ser retornado.

    public static final String NAME = "Generic";

    private static final String CI = "CI";

    @Override
    public Optional<CIInfo> detectCI() {
        String ciEnv = System.getenv(CI);
        if (ciEnv != null && !"false".equals(ciEnv)) {
            return Optional.of(new CIInfo() {
                @Override
                public String name() {
                    return NAME;
                }

/// tip | Dica

Para isso funcionar, você precisa executar `pip install python-dotenv`.

///

### O arquivo `.env` { #the-env-file }

Você poderia ter um arquivo `.env` com:

```bash
ADMIN_EMAIL="******@****.***"

    public static final String NAME = "TeamCity";

    private static final String TEAMCITY_VERSION = "TEAMCITY_VERSION";

    @Override
    public Optional<CIInfo> detectCI() {
        String ciEnv = System.getenv(TEAMCITY_VERSION);
        if (ciEnv != null && !ciEnv.trim().isEmpty()) {
            return Optional.of(new CIInfo() {
                @Override
                public String name() {
                    return NAME;

/// tip | Tipp

Damit das funktioniert, müssen Sie `pip install python-dotenv` ausführen.

///

### Die `.env`-Datei { #the-env-file }

Sie könnten eine `.env`-Datei haben, mit:

```bash