파이썬 **바깥**인 터미널에서(또는 다른 어떤 방법으로든) 환경 변수를 만들고, 그런 다음 **파이썬에서 읽을 수 있습니다**.

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

[`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) 의 두 번째 인자는 반환할 기본값입니다.

제공하지 않으면 기본값은 `None`이며, 여기서는 사용할 기본값으로 `"World"`를 제공합니다.

///

你也可以在 Python **之外**的终端中创建环境变量（或使用任何其他方法），然后在 Python 中**读取**它们。

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 | 提示

第二个参数是 [`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) 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。

///

// according to settings. At each "safe" point it also checks if an
// external quit signal has been received and quits if so. Since the
// healing traversal may be mutating on-disk data when an external
// quit signal is received, this routine cannot quit immediately and
// has to wait until a safe point is reached, such as between scanning
// two objects.

    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Parses the specified string as a single-precision floating point value. The ASCII character
   * {@code '-'} (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Float#parseFloat(String)}, this method returns {@code null} instead of

	if err := globalConfigSys.Init(newObject); err != nil {
		if configRetriableErrors(err) {
			return fmt.Errorf("Unable to initialize config system: %w", err)
		}

		// Any other config errors we simply print a message and proceed forward.
		configLogIf(ctx, fmt.Errorf("Unable to initialize config, some features may be missing: %w", err))
	}

	return nil
}

func setGlobalInternodeInterface(interfaceName string) {

      // TODO(user): verify future behavior - unify logic with getFutureValue in AbstractFuture. This
      // code should be unreachable with correctly implemented Futures.
      // Cancel this future and return.
      // At this point, inputFuture is cancelled and outputFuture doesn't exist, so the value of
      // mayInterruptIfRunning is irrelevant.
      cancel(false);
      return;
    } catch (ExecutionException e) {

             */
            if (aggregating && areAllDependenciesInReactor(session.getProjects(), result.getUnresolvedDependencies())) {
                logger.warn("The following dependencies could not be resolved at this point of the build"
                        + " but seem to be part of the reactor:");

                for (Dependency dependency : result.getUnresolvedDependencies()) {
                    logger.warn("o {}", dependency);

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 [`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) es el valor por defecto a retornar.

Lorsque vous écrivez le code pour documenter un callback, il peut être utile d’imaginer que vous êtes cette *personne développeuse externe*. Et que vous implémentez actuellement l’*API externe*, pas *votre API*.

Adopter temporairement ce point de vue (celui de la *personne développeuse externe*) peut vous aider à trouver plus évident où placer les paramètres, le modèle Pydantic pour le corps, pour la réponse, etc., pour cette *API externe*.

///

        prp.store(out, header);
    }

    /**
     * List the properties in the <code>Config</code>.
     *
     * @param out the print stream to write the properties to
     * @throws IOException if an I/O error occurs
     */

    public static void list(final PrintStream out) throws IOException {
        prp.list(out);
    }

    /**