```Python
q: Annotated[str, Query(default="rick")] = "morty"
```

...because it's not clear if the default value should be `"rick"` or `"morty"`.

So, you would use (preferably):

```Python
q: Annotated[str, Query()] = "rick"
```

...or in older code bases you will find:

```Python
q: str = Query(default="rick")
```

### Advantages of `Annotated`

    return client


def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200
    assert response.json() == [{"username": "Rick"}, {"username": "Morty"}]


def test_users_with_no_token(client: TestClient):
    response = client.get("/users")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

    return client


@needs_py39
def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200
    assert response.json() == [{"username": "Rick"}, {"username": "Morty"}]


@needs_py39
def test_users_with_no_token(client: TestClient):
    response = client.get("/users")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

    return client


def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200
    assert response.json() == [{"username": "Rick"}, {"username": "Morty"}]


def test_users_with_no_token(client: TestClient):
    response = client.get("/users")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

    from fastapi import APIRouter, FastAPI

    app = FastAPI()
    router = APIRouter()


    @router.get("/users/", tags=["users"])
    async def read_users():
        return [{"username": "Rick"}, {"username": "Morty"}]


    app.include_router(router)
    ```
    """

    def __init__(
        self,
        *,

data = {
    "plumbus": {"description": "Freshly pickled plumbus", "owner": "Morty"},
    "portal-gun": {"description": "Gun to create portals", "owner": "Rick"},
}


class OwnerError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except OwnerError as e:
        raise HTTPException(status_code=400, detail=f"Owner error: {e}")


@app.get("/items/{item_id}")