Das zweite Argument für <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> ist der zurückzugebende Defaultwert.

Wenn nicht angegeben, ist er standardmäßig `None`. Hier übergeben wir `"World"` als Defaultwert.

///

Dann könnten Sie dieses Python-Programm aufrufen:

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```console
// Hier legen wir die Umgebungsvariable noch nicht fest

				CheckUser(t, models3[idx], user)
			})
		}
	}

	var none []User
	if err := DB.Where("name in (?)", []string{}).Find(&none).Error; err != nil || len(none) != 0 {
		t.Errorf("errors happened when query find with in clause and zero length parameter: %v, length: %v", err, len(none))
	}
}

func TestQueryWithAssociation(t *testing.T) {

    assertTrue("Expected another permutation, but there was none.", permutations.hasNext());
    assertEquals(expectedPermutation, permutations.next());
  }

  private <T> void assertNoMorePermutations(Iterator<List<T>> permutations) {
    assertFalse("Expected no more permutations, but there was one.", permutations.hasNext());
    try {
      permutations.next();

// corresponding error value. NB When there is more than one error value that
// occurs maximum number of times, the error value returned depends on how
// golang's map orders keys. This doesn't affect correctness as long as quorum
// value is greater than or equal to simple majority, since none of the equally
// maximal values would occur quorum or more number of times.

  }

  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);

  }

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

    List<Short> one = Arrays.asList((short) 1);
    assertThat(Shorts.toArray(one)).isEqualTo(ARRAY1);

    short[] array = {(short) 0, (short) 1, (short) 3};

    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. */

			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 {
		return false, fmt.Errorf("internal error: localLocker.RLock called with more than one resource")
	}
	// If we have too many waiting, reject this at once.

/// tip

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> এর দ্বিতীয় আর্গুমেন্টটি হলো এর ডিফল্ট ভ্যালু যা রিটার্ন করা হবে।

যদি এটি দেওয়া না হয়, ডিফল্টভাবে `None` ব্যবহৃত হবে, এখানে আমরা ডিফল্ট ভ্যালু হিসেবে `"World"` ব্যবহার করেছি।

///

তারপরে পাইথন প্রোগ্রামটিকে নিম্নোক্তভাবে কল করা যাবেঃ

//// tab | লিনাক্স, ম্যাকওএস, উইন্ডোজ Bash

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/// 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.

Si no se proporciona, es `None` por defecto; aquí proporcionamos `"World"` como el valor por defecto para usar.

///

Luego podrías llamar a ese programa Python:

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

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```console