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}
```

השרת אמול להתאתחל אוטומטית (מאחר והוספתם <code dir="ltr">--reload</code> לפקודת `uvicorn` שלמעלה).

### שדרוג התיעוד האינטרקטיבי

ge=".content-wrapper iframe",pe=".content-wrapper.iframe-mode .nav",me=".content-wrapper.iframe-mode .navbar-nav",ve=me+" .nav-item",_e=me+" .nav-link",be=".content-wrapper.iframe-mode .tab-content",ye=be+" .tab-empty",Ce=be+" .tab-loading",we=be+" .tab-pane",xe=".main-sidebar .nav-item > a.nav-link",Ie=".main-header .nav-item a.nav-link",Te=".main-header a.dropdown-item",Se="iframe-mode",je="iframe-mode-fullscreen",ke={onTabClick:function(e){return e},onTabChanged:function(e){return e},onTabCre...

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})

                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item"><la:link href="/admin/dict">
                                <la:message key="labels.dict_list_link"/>
                            </la:link></li>
                            <li class="breadcrumb-item"><la:link href="../list/1/?dictId=${f:u(dictId)}">
                                <la:message key="labels.dict_kuromoji_list_link"/>

                        },
                    },
                    "summary": "Read Item",
                    "operationId": "read_item_items__item_id__get",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "integer"},
                            "name": "item_id",

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})

    }
  ]
}
```

As `needy` is a required parameter, you would need to set it in the URL:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...this would work:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

And of course, you can define some parameters as required, some as having a default value, and some entirely optional:

        }
        if (elements.length > 1) {
          /*
           * When a test requests a multiset with duplicates, our plan of
           * "add an extra item 0 to A and an extra item 1 to B" really means
           * "add an extra item 0 to A and B," which isn't what we want.
           */
          if (!Objects.equal(elements[0], elements[1])) {
            multiset2.add(elements[1], 2);
          }
        }

            "type": "value_error.missing"
        }
    ]
}
```

`needy`는 필수 매개변수이므로 URL에 반드시 설정해줘야 합니다:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...아래처럼 작동합니다:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

그리고 물론, 일부 매개변수는 필수로, 다른 일부는 기본값을, 또 다른 일부는 선택적으로 선언할 수 있습니다:

```Python hl_lines="10"

{!../../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；