app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

기본값 `None`을 `Query(None)`으로 바꿔야 하므로, `Query`의 첫 번째 매개변수는 기본값을 정의하는 것과 같은 목적으로 사용됩니다.

그러므로:

```Python
q: Optional[str] = Query(None)
```

...위 코드는 아래와 동일하게 매개변수를 선택적으로 만듭니다:

```Python
q: Optional[str] = None
```

하지만 명시적으로 쿼리 매개변수를 선언합니다.

/// info | 정보

FastAPI는 다음 부분에 관심이 있습니다:

```Python
= None
```

또는:

```Python
= Query(None)

/// note | Nota

FastAPI sabrá que el valor de `q` no es requerido debido al valor por defecto `= None`.

El `str | None` (Python 3.10+) o `Union` en `Union[str, None]` (Python 3.9+) no es utilizado por FastAPI para determinar que el valor no es requerido, sabrá que no es requerido porque tiene un valor por defecto de `= None`.

Pero agregar las anotaciones de tipos permitirá que tu editor te brinde un mejor soporte y detecte errores.

Your response model could have default values, like:

{* ../../docs_src/response_model/tutorial004_py310.py hl[9,11:12] *}

* `description: Union[str, None] = None` (or `str | None = None` in Python 3.10) has a default of `None`.
* `tax: float = 10.5` has a default of `10.5`.
* `tags: List[str] = []` has a default of an empty list: `[]`.

    assert response.status_code == 200
    assert response.json() == {
        "host": "testserver",
        "save_data": True,
        "if_modified_since": None,
        "traceparent": None,
        "x_tag": [],
    }


def test_header_param_model_invalid(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 422

 *
 */
public interface BeanConfigurationRequest {

    /**
     * Gets the bean to configure. Eventually, a valid request must have a bean set.
     *
     * @return The bean to configure, or {@code null} if none.
     */
    Object getBean();

    /**
     * Sets the bean to configure. Eventually, a valid request must have a bean set.
     *
     * @param bean The bean to configure, may be {@code null}.

 */
@Deprecated(since = "4.0.0")
public interface SettingsBuildingRequest {

    /**
     * Gets the global settings file.
     *
     * @return The global settings file or {@code null} if none.
     */
    File getGlobalSettingsFile();

    /**
     * Sets the global settings file. A non-existent settings file is equivalent to empty settings. If both user

As, by default, singular values are interpreted as query parameters, you don't have to explicitly add a `Query`, you can just do:

```Python
q: Union[str, None] = None
```

Or in Python 3.10 and above:

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

For example:

{* ../../docs_src/body_multiple_params/tutorial004_an_py310.py hl[28] *}


/// info

from starlette.responses import StreamingResponse as StreamingResponse  # noqa

try:
    import ujson
except ImportError:  # pragma: nocover
    ujson = None  # type: ignore


try:
    import orjson
except ImportError:  # pragma: nocover
    orjson = None  # type: ignore


class UJSONResponse(JSONResponse):
    """
    JSON response using the high-performance ujson library to serialize data to JSON.

from sqlmodel import Field, Session, SQLModel, create_engine, select


class Hero(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    age: int | None = Field(default=None, index=True)
    secret_name: str


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"

connect_args = {"check_same_thread": False}