$ echo "Hello $MY_NAME"

    Hello Wade Wilson
    ```

    </div>

=== "Windows PowerShell"

    <div class="termy">

    ```console
    // Erstelle eine Umgebungsvariable MY_NAME
    $ $Env:MY_NAME = "Wade Wilson"

    // Verwende sie mit anderen Programmen, etwa
    $ echo "Hello $Env:MY_NAME"

    Hello Wade Wilson
    ```

    </div>

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

Und wenn Sie auf <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> gehen, sehen Sie die Response von FastAPI:

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

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": False})


@app.get("/users/{username}")
async def read_user(username: str):

        assert orjson is not None, "orjson must be installed"
        return orjson.dumps(content, option=orjson.OPT_INDENT_2)


@app.get("/", response_class=CustomORJSONResponse)
async def main():

client = TestClient(app, root_path="/api/v1")


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

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

def test_api(client: TestClient):
    response = client.get("/users/john")
    assert response.status_code == 200, response.text

    ), "default configs should be preserved"


def test_get_users():
    response = client.get("/users/foo")
    assert response.status_code == 200, response.text

def test_api(client: TestClient):
    response = client.get("/users/john")
    assert response.status_code == 200, response.text

```Python hl_lines="9-14  17"
{!../../../docs_src/custom_response/tutorial009c.py!}
```

Statt:

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

... wird die Response jetzt Folgendes zurückgeben:

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

Natürlich werden Sie wahrscheinlich viel bessere Möglichkeiten finden, Vorteil daraus zu ziehen, als JSON zu formatieren. 😉