"FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
    )
  }

  /** Inspect how many runnables have been enqueued. If none then we're truly sequential. */
  @Test fun singleQueueIsSerial() {
    redQueue.execute("task one", 100.µs) {
      log += "one:run@${taskFaker.nanoTime} parallel=${taskFaker.isParallel}"
    }

print(f"Hello {name} from Python")
```

/// tip

第二個參數是 <a href="https://docs.python.org/zh-tw/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 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

				*lri = append((*lri)[:index], (*lri)[index+1:]...)
				l.lockMap[name] = *lri
			}
			delete(l.lockUID, formatUUID(args.UID, entry.idx))
			return true
		}
	}

	// None found return false, perhaps entry removed in previous run.
	return false
}

func (l *localLocker) RLock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
	if len(args.Resources) != 1 {

```Python
from typing import Union
from fastapi import Cookie, FastAPI, Header, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
def main(
    item_id: int = Path(gt=0),
    query: Union[str, None] = Query(default=None, max_length=10),
    session: Union[str, None] = Cookie(default=None, min_length=3),

    /** Constant representing automatic mode. */
    public static final String AUTO = "auto";

    /** Constant representing no value or empty state. */
    public static final String NONE = "none";

    // ============================================================
    // Item/Field Identifiers
    // ============================================================

    SerializableTester.reserializeAndAssert(Floats.stringConverter());
  }

  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};

    SerializableTester.reserializeAndAssert(Ints.stringConverter());
  }

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

    List<Integer> one = Arrays.asList((int) 1);
    assertThat(Ints.toArray(one)).isEqualTo(ARRAY1);

    int[] array = {(int) 0, (int) 1, (int) 0xdeadbeef};

    SerializableTester.reserializeAndAssert(Floats.stringConverter());
  }

  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};

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: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile

Ahora, en el mismo directorio del proyecto, crea un archivo `Dockerfile` con:

```{ .dockerfile .annotate }
# (1)!

	newSignature := getSignature(signingKey, stringToSign)

	// Verify if signature match.
	if !compareSignatureV4(newSignature, signV4Values.Signature) {
		return ErrSignatureDoesNotMatch
	}

	// Return error none.
	return ErrNone