`Optional[Something]` насправді є скороченням для `Union[Something, None]`, вони еквівалентні.

Це також означає, що в Python 3.10 ви можете використовувати `Something | None`:

//// tab | Python 3.8 і вище

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009.py!}
```

    //     fgh[b]c|[a]de -> fgh[a]c|[b]de. Finally we need to swap [c] with [b]:
    //     fgha[c]|[b]de -> fgha[b]|[c]de. Because these two blocks are the same size, we are done.
    // The Dolphin algorithm is attractive because it does the fewest array reads and writes: each
    // array slot is read and written exactly once. However, it can have very poor memory locality:

## Optionale Parameter

Auf die gleiche Weise können Sie optionale Query-Parameter deklarieren, indem Sie deren Defaultwert auf `None` setzen:

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

In diesem Fall wird der Funktionsparameter `q` optional, und standardmäßig `None` sein.

/// check

	docker-compose -f docker-compose-site1.yaml rm -s -f || true
	docker-compose -f docker-compose-site2.yaml rm -s -f || true
	for volume in $(docker volume ls -q | grep minio); do
		docker volume rm ${volume} || true
	done

	docker system prune -f || true
	docker volume prune -f || true
	docker volume rm $(docker volume ls -q -f dangling=true) || true
}

cleanup

if [ ! -f ./mc ]; then

		aws --endpoint-url http://localhost:"$start_port" s3api upload-part \
			--upload-id "$uploadId" --bucket bucket --key obj-1 \
			--part-number "$i" --body ./file-5mib
	done
	for i in {1..6}; do
		find ${WORK_DIR}/disk${i}/.minio.sys/multipart/ -type f -name "part.1" -delete
	done
	cat <<EOF >parts.json
{
    "Parts": [
        {
            "PartNumber": 1,
            "ETag": "5f363e0e58a95f06cbe9bbc662c5dfb6"
        },

`Optional[Something]` là một cách viết ngắn gọn của `Union[Something, None]`, chúng là tương đương nhau.

Điều này cũng có nghĩa là trong Python 3.10, bạn có thể sử dụng `Something | None`:

//// tab | Python 3.10+

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

/**
 * A {@link FutureTask} that also implements the {@link ListenableFuture} interface. Unlike {@code
 * FutureTask}, {@code ListenableFutureTask} does not provide an overrideable {@link
 * FutureTask#done() done()} method. For similar functionality, call {@link #addListener}.
 *
 * <p>Few users should use this class. It is intended primarily for those who are implementing an

nr_servers=4

addr="localhost"
args=""
for ((i = 0; i < $((nr_servers)); i++)); do
	args="$args $scheme://$addr:$((9100 + i))/${HOME}/tmp/dist/path1/$i"
done

echo $args

for ((i = 0; i < $((nr_servers)); i++)); do
	(minio server --address ":$((9100 + i))" $args 2>&1 >/tmp/log$i.txt) &
done

sleep 10s

if [ ! -f ./mc ]; then
	wget --quiet -O ./mc https://dl.minio.io/client/mc/release/linux-amd64/./mc &&
		chmod +x mc
fi

echo "done"

if [ ! -f ./mc ]; then
	echo -n "Downloading MinIO client ..."
	wget -O mc https://dl.min.io/client/mc/release/linux-amd64/mc &&
		chmod +x mc
	echo "done"
fi

export MC_HOST_minio1=https://minio:minio123@localhost:9001
export MC_HOST_minio2=https://minio:minio123@localhost:9002

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):