prefix_router = APIRouter()
native_prefix_route = APIRouter(prefix="/native")
app = FastAPI()


@app.websocket_route("/")
async def index(websocket: WebSocket):
    await websocket.accept()
    await websocket.send_text("Hello, world!")
    await websocket.close()


@router.websocket_route("/router")
async def routerindex(websocket: WebSocket):
    await websocket.accept()
    await websocket.send_text("Hello, router!")

from docs_src.first_steps.tutorial001 import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        ("/", 200, {"message": "Hello World"}),
        ("/nonexistent", 404, {"detail": "Not Found"}),
    ],
)
def test_get_path(path, expected_status, expected_response):
    response = client.get(path)
    assert response.status_code == expected_status

    PrintWriter w = new PrintWriter(Files.newWriter(temp, UTF_8));
    w.println("hello");
    w.println("");
    w.println(" world  ");
    w.println("");
    w.close();

    assertEquals("hello", Files.readFirstLine(temp, UTF_8));
    assertEquals(ImmutableList.of("hello", "", " world  ", ""), Files.readLines(temp, UTF_8));

    assertTrue(temp.delete());
  }

      label: Context (optional)
      description: |
        How has this issue affected you? What are you trying to accomplish?
        Providing context helps us come up with a solution that is most useful in the real world
    validations:

  /**
   * Flush a {@link Flushable}, with control over whether an {@code IOException} may be thrown.
   *
   * <p>If {@code swallowIOException} is true, then we don't rethrow {@code IOException}, but merely
   * log it.
   *
   * @param flushable the {@code Flushable} object to be flushed.
   * @param swallowIOException if true, don't propagate IO exceptions thrown by the {@code flush}
   *     method

```Python hl_lines="3"
import os

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

/// tip | "Tipp"

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.

///

     * @param model The model to validate, must not be {@code null}.
     * @param request The model building request that holds further settings, must not be {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     */
    default void validateFileModel(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
        // do nothing
    }

    /**

from docs_src.behind_a_proxy.tutorial004 import app

client = TestClient(app)


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "openapi": "3.1.0",

    PrintWriter w = new PrintWriter(Files.newWriter(temp, UTF_8));
    w.println("hello");
    w.println("");
    w.println(" world  ");
    w.println("");
    w.close();

    assertEquals("hello", Files.readFirstLine(temp, UTF_8));
    assertEquals(ImmutableList.of("hello", "", " world  ", ""), Files.readLines(temp, UTF_8));

    assertTrue(temp.delete());
  }

🖼 👆 💪 ✔️ 📁 `main.py` ⏮️:

```Python hl_lines="3"
import os

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

/// tip

🥈 ❌ <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 🔢 💲 📨.

🚥 🚫 🚚, ⚫️ `None` 🔢, 📥 👥 🚚 `"World"` 🔢 💲 ⚙️.

///

⤴️ 👆 💪 🤙 👈 🐍 📋:

<div class="termy">

```console