Por ejemplo, podrías tener un archivo `main.py` con:

```Python hl_lines="3"
import os

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

/// tip | Consejo

El segundo argumento de <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> es el valor por defecto a retornar.

            if (connected) {
                return;
            }
            final String endpoint = System.getenv().get("S3_ENDPOINT");
            final String accessKey = System.getenv().get("S3_ACCESS_KEY");
            final String secretKey = System.getenv().get("S3_SECRET_KEY");
            final String region = System.getenv().getOrDefault("S3_REGION", "us-east-1");

            // Validate endpoint before attempting connection

            if (connected) {
                return;
            }
            final String projectId = System.getenv("GCS_PROJECT_ID");
            final String endpoint = System.getenv("GCS_ENDPOINT");
            final String credentialsFile = System.getenv("GCS_CREDENTIALS_FILE");

            // Validate projectId before attempting connection
            if (StringUtil.isBlank(projectId)) {

import os
from typing import Any

from pdm.backend.hooks import Context

TIANGOLO_BUILD_PACKAGE = os.getenv("TIANGOLO_BUILD_PACKAGE", "fastapi")


def pdm_build_initialize(context: Context) -> None:
    metadata = context.config.metadata
    # Get custom config for the current package, from the env var
    config: dict[str, Any] = context.config.data["tool"]["tiangolo"][
        "_internal-slim-build"
    ]["packages"].get(TIANGOLO_BUILD_PACKAGE)

        }
        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");

                System.getProperties().entrySet().stream().forEach(e -> logger.debug("Property: {}={}", e.getKey(), e.getValue()));
                System.getenv().entrySet().forEach(e -> logger.debug("Env: {}={}", e.getKey(), e.getValue()));
                logger.debug("Options: options={}", options);
            } catch (final Exception e) {
                // ignore
            }

                System.getProperties().entrySet().stream().forEach(e -> logger.debug("Property: {}={}", e.getKey(), e.getValue()));
                System.getenv().entrySet().forEach(e -> logger.debug("Env: {}={}", e.getKey(), e.getValue()));
                logger.debug("Options: options={}", options);
            } catch (final Exception e) {
                // ignore
            }

                System.getProperties().entrySet().stream().forEach(e -> logger.debug("Property: {}={}", e.getKey(), e.getValue()));
                System.getenv().entrySet().forEach(e -> logger.debug("Env: {}={}", e.getKey(), e.getValue()));
                logger.debug("Options: options={}", options);
            } catch (final Exception e) {
                // ignore
            }

    }

    /**
     * Gets a map of environment variables.
     *
     * @return A map of environment variables.
     */
    protected Map<String, String> getEnvMap() {
        return System.getenv();
    }

    /**
     * Gets the version of the Fess application.
     *
     * @return The version string.
     */
    public String getVersion() {
        return version;
    }

    if mod_name in sys.modules:
        del sys.modules[mod_name]
    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    main_mod = importlib.import_module(mod_name)
    return TestClient(main_mod.app)


def test_settings_validation_error(mod_name: str, monkeypatch: MonkeyPatch):
    monkeypatch.delenv("ADMIN_EMAIL", raising=False)
    if mod_name in sys.modules: