import os

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

/// tip

第二個參數是 [`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) 的預設回傳值。

如果沒有提供，預設值為 `None`，這裡我們提供 `"World"` 作為預設值。

///

然後你可以呼叫這個 Python 程式：

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 這裡我們還沒有設定環境變數
$ python main.py

// 因為我們沒有設定環境變數，所以我們得到的是預設值

	for !errState {
		select {
		case <-m.ctx.Done():
			if debugPrint {
				fmt.Println("Client sending disconnect to mux", m.MuxID)
			}
			m.addErrorNonBlockingClose(errResp, context.Cause(m.ctx))
			errState = true
			continue
		case <-pingTimer:
			if !m.doPing(errResp) {
				errState = true
				continue
			}
		case req, ok := <-requests:
			if !ok {
				// Done send EOF
				if debugPrint {

import os

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

/// tip | 豆知識

[`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) の第2引数は、返されるデフォルト値です。

指定しない場合、デフォルトは`None`ですが、ここでは使用するデフォルト値として`"World"`を指定しています。

///

次に、このPythonプログラムを呼び出します。

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// ここではまだ環境変数を設定していません
$ python main.py

    public static final String READY = "ready";

    /** Status constant representing running state. */
    public static final String RUNNING = "running";

    /** Status constant representing done/completed state. */
    public static final String DONE = "done";

    /** Status constant representing successful operation. */
    public static final String OK = "ok";

    /** Status constant representing failed operation. */

      Header("expect", ""),
      Header("expires", ""),
      Header("from", ""),
      Header("host", ""),
      Header("if-match", ""),
      Header("if-modified-since", ""),
      Header("if-none-match", ""),
      Header("if-range", ""),
      Header("if-unmodified-since", ""),
      Header("last-modified", ""),
      Header("link", ""),
      Header("location", ""),
      Header("max-forwards", ""),

        logger.log(Level.SEVERE, "Error cleaning up after reference.", t);
      }
    }
  }

  /**
   * Iterates through the given loaders until it finds one that will load Finalizer.
   *
   * @return a {@link Class} for {@link Finalizer} or {@code null} if none of the loaders load it
   */
  private static @Nullable Class<?> loadFinalizer(FinalizerLoader... loaders) {
    for (FinalizerLoader loader : loaders) {

  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Double> none = Arrays.<Double>asList();
    assertThat(Doubles.toArray(none)).isEqualTo(EMPTY);

    List<Double> one = Arrays.asList(1.0);
    assertThat(Doubles.toArray(one)).isEqualTo(ARRAY1);

    double[] array = {0.0, 1.0, Math.PI};

    List<Double> three = Arrays.asList(0.0, 1.0, Math.PI);

```Python
from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: str | None = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile { #dockerfile }

이제 같은 프로젝트 디렉터리에 다음 내용으로 `Dockerfile` 파일을 만듭니다:

```{ .dockerfile .annotate }
# (1)!
FROM python:3.14

                Collections.sort(listedButNotFound)
                listedButNotFound = listedButNotFound.collect {'    ' + it}
                message += "Expected unconverted snippets but none found in:\n"
                message += listedButNotFound.join("\n")
            }
            if (false == unconvertedCandidates.isEmpty()) {
                List<String> foundButNotListed =

  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Float> none = Arrays.<Float>asList();
    assertThat(Floats.toArray(none)).isEqualTo(EMPTY);

    List<Float> one = Arrays.asList(1.0f);
    assertThat(Floats.toArray(one)).isEqualTo(ARRAY1);

    float[] array = {0.0f, 1.0f, 3.0f};

    List<Float> three = Arrays.asList(0.0f, 1.0f, 3.0f);