if err != nil {
		return meta, false, err
	}
	sys.Lock()
	sys.metadataMap[bucket] = meta
	sys.Unlock()

	return meta, true, nil
}

// Init - initializes bucket metadata system for all buckets.
func (sys *BucketMetadataSys) Init(ctx context.Context, buckets []string, objAPI ObjectLayer) error {
	if objAPI == nil {
		return errServerNotInitialized
	}

	sys.objAPI = objAPI

                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item active"><la:link href="/admin/elevateword">
                                <la:message key="labels.elevate_word_link_list"/>
                            </la:link></li>
                            <li class="breadcrumb-item active"><a href="#"><la:message
                                    key="labels.elevate_word_link_download"/></a></li>

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    *, item_id: int = Path(title="The ID of the item to get", ge=1), q: str
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

```
{
  "item": "The Foo Wrestlers"
}
```

Mas se o cliente faz uma requisição para `http://example.com/items/bar` (ou seja, um não existente `item_id "bar"`), esse cliente receberá um HTTP status code 404 (o erro "não encontrado" — *not found error*), e uma resposta JSON:

```JSON
{
  "detail": "Item not found"
}
```

/// tip | "Dica"

from typing import Annotated, Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[Union[str, None], Query(alias="item-query")] = None):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

{!../../docs_src/dataclasses/tutorial003.py!}
```

1. 本例依然要从标准的 `dataclasses` 中导入 `field`；

2. 使用 `pydantic.dataclasses` 直接替换 `dataclasses`；

3. `Author` 数据类包含 `Item` 数据类列表；

4. `Author` 数据类用于 `response_model` 参数；

5. 其它带有数据类的标准类型注解也可以作为请求体；

    本例使用的是 `Item` 数据类列表；

6. 这行代码返回的是包含 `items` 的字典，`items` 是数据类列表；

    FastAPI 仍能把数据<abbr title="把数据转换为可以传输的格式">序列化</abbr>为 JSON；

{!> ../../docs_src/path_operation_advanced_configuration/tutorial007_pv1.py!}
```

////

/// info

In Pydantic Version 1 hieß die Methode zum Abrufen des JSON-Schemas für ein Modell `Item.schema()`, in Pydantic Version 2 heißt die Methode `Item.model_json_schema()`.

///

				HTTPClient: c.client.HTTPClient,
			}

			var item madmin.ItemState
			if _, err := client.Status(ctx); err == nil {
				item = madmin.ItemOnline
			} else {
				item = madmin.ItemOffline
			}
			results[i] = Result{
				Endpoint:  c.client.Endpoints[i],
				ItemState: item,
			}
		}(i)
	}
	wg.Wait()

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(default=None, alias="item-query")):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

    return {"item_id": item_id, "q": q}


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

সার্ভারটি স্বয়ংক্রিয়ভাবে পুনরায় লোড হওয়া উচিত (কারণ আপনি উপরের `uvicorn` কমান্ডে `--reload` যোগ করেছেন)।

### ক্রিয়াশীল API নির্দেশিকা নথি উন্নীতকরণ