Раніше ми мали таку анотацію типу:

```Python
q: str | None = None
```

Тепер ми загорнемо її у `Annotated`, і отримаємо:

```Python
q: Annotated[str | None] = None
```

Обидві ці версії означають одне й те саме: `q` — це параметр, який може бути `str` або `None`, і за замовчуванням має значення `None`.

А тепер переходимо до цікавого! 🎉

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "p"],
                "msg": "Field required",
                "input": IsOneOf(None, {}),
            }
        ]
    }


@pytest.mark.parametrize(
    "path",
    ["/required-str", "/model-required-str"],
)
def test_required_str(path: str):
    client = TestClient(app)

app = FastAPI()


class Item(BaseModel):
    name: str | None = None
    description: str | None = None
    price: float | None = None
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}

  float: none;
}

.daterangepicker.single .drp-selected {
  display: none;
}

.daterangepicker.show-calendar .drp-calendar {
  display: block;
}

.daterangepicker.show-calendar .drp-buttons {
  display: block;
}

.daterangepicker.auto-apply .drp-buttons {
  display: none;
}

.daterangepicker .drp-calendar {
  display: none;

    "field (e.g. Union[Response, dict, None]) you can disable generating the "
    "response model from the type annotation with the path operation decorator "
    "parameter response_model=None. Read more: "
    "https://fastapi.tiangolo.com/tutorial/response-model/"
)


def create_model_field(
    name: str,
    type_: Any,
    default: Any | None = Undefined,
    field_info: FieldInfo | None = None,

from fastapi import APIRouter, FastAPI
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: str | None = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool


invoices_callback_router = APIRouter()


@invoices_callback_router.post(

            )
        )
        if not ok:
            raise e
    else:
        await anyio.to_thread.run_sync(
            cm.__exit__, None, None, None, limiter=exit_limiter

Nous avions cette annotation de type :

```Python
q: str | None = None
```

Ce que nous allons faire, c’est l’englober avec `Annotated`, de sorte que cela devienne :

```Python
q: Annotated[str | None] = None
```

Les deux versions signifient la même chose, `q` est un paramètre qui peut être une `str` ou `None`, et par défaut, c’est `None`.

Passons maintenant aux choses amusantes. 🎉

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["body", "p"],
                "msg": "Field required",
                "input": IsOneOf(None, {}),
            }
        ]
    }


@pytest.mark.parametrize(
    "path",
    ["/required-str", "/model-required-str"],
)
def test_required_str(path: str):
    client = TestClient(app)

        "item_id": 5,
        "item": {
            "name": "Foo",
            "price": 50.5,
            "description": None,
            "tax": None,
        },
        "q": "bar",
    }


def test_post_no_body_q_bar(client: TestClient):
    response = client.put("/items/5?q=bar", json=None)
    assert response.status_code == 200
    assert response.json() == {"item_id": 5, "q": "bar"}