Аналогично, вы можете объявлять необязательные query-параметры, установив их значение по умолчанию, равное `None`:

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

В этом случае, параметр  `q` будет не обязательным и будет иметь значение `None` по умолчанию.

/// check | Важно

查询参数的值就是：

* `skip=20`：在 URL 中设定的值
* `limit=10`：使用默认值

## 可选参数

同理，把默认值设为 `None` 即可声明**可选的**查询参数：

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

本例中，查询参数 `q` 是可选的，默认值为 `None`。

/// check | 检查

注意，**FastAPI** 可以识别出 `item_id` 是路径参数，`q` 不是路径参数，而是查询参数。

///

/// note | 笔记

因为默认值为 `= None`，FastAPI 把 `q` 识别为可选参数。

package lifecycle

import (
	"encoding/xml"
	"io"

	"github.com/minio/minio-go/v7/pkg/tags"
)

var errInvalidFilter = Errorf("Filter must have exactly one of Prefix, Tag, or And specified")

// Filter - a filter for a lifecycle configuration Rule.
type Filter struct {
	XMLName xml.Name `xml:"Filter"`
	set     bool

	Prefix Prefix

			return res, err
		}
	}

	var mu sync.Mutex
	var uploadTimes madmin.TimeDurations
	wg.Add(opts.concurrency)
	for i := 0; i < opts.concurrency; i++ {
		go func(i int) {
			defer wg.Done()
			for {
				t := time.Now()
				reader := newRandomReader(opts.objectSize)
				tmpObjName := pathJoin(objNamePrefix, fmt.Sprintf("%d/%d", i, objCountPerThread[i]))

    client = TestClient(mod.app)
    return client


@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"X-Token values": None}),
        ("/items", {"x-token": "foo"}, 200, {"X-Token values": ["foo"]}),
        (
            "/items",
            [("x-token", "foo"), ("x-token", "bar")],
            200,

	}
}

// bucketPop should be called when a bucket is done decommissioning.
// Adds the bucket to the list of decommissioned buckets and updates resume numbers.
func (pd *PoolDecommissionInfo) bucketPop(bucket string) bool {
	pd.DecommissionedBuckets = append(pd.DecommissionedBuckets, bucket)
	for i, b := range pd.QueuedBuckets {
		if b == bucket {
			// Bucket is done.

import org.apache.maven.api.cli.cisupport.CIInfo;

/**
 * CI detector helper: it uses service discovery to discover {@link CIDetector}s. If resulting list has more than
 * one element, it will remove the {@link GenericCIDetector} result, assuming a more specific one is also present.
 */
public final class CIDetectorHelper {
    private CIDetectorHelper() {}

    public static List<CIInfo> detectCI() {

But we also pass a `list` of scopes, in this case with just one scope: `items` (it could have more).

And the dependency function `get_current_active_user` can also declare sub-dependencies, not only with `Depends` but also with `Security`. Declaring its own sub-dependency function (`get_current_user`), and more scope requirements.

In this case, it requires the scope `me` (it could require more than one scope).

/// note

All replication failures are picked up by the scanner which runs at a one minute frequency, each time scanning up to a sixteenth of the namespace. Object versions marked `PENDING` or `FAILED` are re-queued for replication.

    assert response.json() == {
        "name": "Special Offer",
        "description": None,
        "price": 38.6,
        "items": [
            {
                "name": "Foo",
                "description": None,
                "price": 35.4,
                "tax": None,
                "tags": [],
                "images": [
                    {