```txt
Hello, World from Flask!
```

Ve eğer [http://localhost:8000/v2](http://localhost:8000/v2) adresine giderseniz, FastAPI'den gelen response'u göreceksiniz:

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

@router.route("/items/")
def read_items(request: Request):
    return JSONResponse({"hello": "world"})


app.include_router(router)

client = TestClient(app)


def test_sub_router():
    response = client.get("/items/")
    assert response.status_code == 200, response.text

Wenn Sie keinen spezifischen Wert haben wollen, sondern der Parameter einfach optional sein soll, dann setzen Sie den Defaultwert auf `None`.

Aber wenn Sie wollen, dass ein Query-Parameter erforderlich ist, vergeben Sie einfach keinen Defaultwert:

{* ../../docs_src/query_params/tutorial005_py310.py hl[6:7] *}

// call of panic. If recover is called outside the deferred function it will
// not stop a panicking sequence. In this case, or when the goroutine is not
// panicking, recover returns nil.
//
// Prior to Go 1.21, recover would also return nil if panic is called with
// a nil argument. See [panic] for details.
func recover() any

// The print built-in function formats its arguments in an

    /*
     * For example, if concentration=2.0, the following takes the square root of
     * the uniformly-distributed random integer, then truncates any fractional
     * part, so higher integers would appear (in this case linearly) more often
     * than lower ones.
     */
    return (int) Math.pow(a, 1.0 / concentration);
  }

  @AfterExperiment
  void tearDown() {
    double req = requests.get();

   * some cases it may alter the input. For example, if the factory returns a sliced view of a
   * source created with some given bytes, this method would return a subsequence of the given
   * (byte[]) data.
   */
  T getExpected(T data);

  /** Cleans up anything created when creating the source or sink. */
  void tearDown() throws IOException;

  static final NaturalOrdering INSTANCE = new NaturalOrdering();

  /*
   * TODO: b/287198172 - Consider eagerly initializing these, maybe making them static. But that
   * would lead to at least slighly more work at startup time.
   */
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsFirst;
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsLast;

    // TODO this is only to provide a project for plugins that don't need a project to execute but need some
    // of the values from a MavenProject. Ideally this should be something internal and nothing outside Maven
    // would ever need this so it should not be exposed in a public API
    MavenProject buildStandaloneSuperProject(ProjectBuilderConfiguration configuration) throws ProjectBuildingException;

            current = classesContainingMethod.get(i)
            if (!isInternal(current)) {
                // there's another public super class which contains target method
                // it would be reported somewhere else
                return false
            }
        }

        // I'm the top public class which contains target method
        return true
    }

    /*
     * For example, if concentration=2.0, the following takes the square root of
     * the uniformly-distributed random integer, then truncates any fractional
     * part, so higher integers would appear (in this case linearly) more often
     * than lower ones.
     */
    return (int) Math.pow(a, 1.0 / concentration);
  }

  @AfterExperiment
  void tearDown() {
    double req = requests.get();