import os

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

/// tip

Het tweede argument van <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is de standaardwaarde die wordt geretourneerd.

Als je dit niet meegeeft, is de standaardwaarde `None`. In dit geval gebruiken we standaard `"World"`.

///

     * {@code <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the
     * exception is thrown so this information is merely meant to assist the user.
     *
     * @return The identifier of the POM or an empty string if not known, never {@code null}.
     */
    public String getModelId() {

* **Kort**: Minimaliseer codeduplicatie. Elke parameterdeclaratie ondersteunt meerdere functionaliteiten. Minder bugs.
* **Robust**: Code gereed voor productie. Met automatische interactieve documentatie.

    assertEquals(TypeToken.of(String.class), invokable.getParameters().get(1).getType());
  }

  public void testAnonymousClassDefaultConstructor() {
    final int i = 1;
    final String s = "hello world";
    Class<?> anonymous =
        new Runnable() {
          @Override
          public void run() {
            System.out.println(s + i);
          }
        }.getClass();

    assertEquals(TypeToken.of(String.class), invokable.getParameters().get(1).getType());
  }

  public void testAnonymousClassDefaultConstructor() {
    final int i = 1;
    final String s = "hello world";
    Class<?> anonymous =
        new Runnable() {
          @Override
          public void run() {
            System.out.println(s + i);
          }
        }.getClass();

            .omitNullValues()
            .add("field1", null)
            .add("field2", "Googley")
            .add("field3", "World")
            .toString();
    assertEquals("TestClass{field2=Googley, field3=World}", toTest);
  }

  @GwtIncompatible // Class names are obfuscated in GWT
  public void testToStringOmitEmptyValues_manyFieldsFirstEmpty() {
    String toTest =

        StringSource source = new StringSource("Hello World!");

        try (InputStream is = source.getInputStream();
                Scanner scanner = new Scanner(is)) {
            assertEquals("Hello World!", scanner.nextLine());
        }
    }

    @Test
    void testGetLocation() {
        StringSource source = new StringSource("Hello World!");
        assertEquals("(memory)", source.getLocation());

```

Bu satır, yerel makinenizde uygulamanızın çalıştığı bağlantıyı gösterir.

### Kontrol Edelim

Tarayıcınızı açıp <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a> bağlantısına gidin.

Şu şekilde bir JSON yanıtı ile karşılaşacağız:

```JSON
{"message": "Hello World"}
```

### Etkileşimli API Dokümantasyonu

package org.apache.maven.embedder;

/**
 * Hello world!
 *
 */
public class App
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
    }

)
def test_router_events(state: State) -> None:
    app = FastAPI()

    @app.get("/")
    def main() -> Dict[str, str]:
        return {"message": "Hello World"}

    @app.on_event("startup")
    def app_startup() -> None:
        state.app_startup = True

    @app.on_event("shutdown")
    def app_shutdown() -> None:
        state.app_shutdown = True