Par exemple, le modèle ci-dessus déclare un JSON « `object` » (ou `dict` Python) tel que :

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

{* ../../docs_src/security/tutorial003_an_py310.py hl[82:85] *}

#### `**user_dict` Hakkında { #about-user-dict }

`UserInDB(**user_dict)` şu anlama gelir:

*`user_dict` içindeki key ve value’ları doğrudan key-value argümanları olarak geçir; şu ifadeyle eşdeğerdir:*

```Python
UserInDB(

**Swagger UI** использует файлы:

* [`swagger-ui-bundle.js`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js)
* [`swagger-ui.css`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css)

А **ReDoc** использует файл:

* [`redoc.standalone.js`](https://cdn.jsdelivr.net/npm/redoc@2/bundles/redoc.standalone.js)

    for item in items:
        yield item


@app.get("/items/stream-sync-no-annotation", response_class=EventSourceResponse)
def sse_items_sync_no_annotation():
    yield from items


@app.get("/items/stream-dict", response_class=EventSourceResponse)
async def sse_items_dict():
    for item in items:
        yield {"name": item.name, "description": item.description}

**Swagger UI** verwendet folgende Dateien:

* [`swagger-ui-bundle.js`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js)
* [`swagger-ui.css`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css)

Und **ReDoc** verwendet diese Datei:

* [`redoc.standalone.js`](https://cdn.jsdelivr.net/npm/redoc@2/bundles/redoc.standalone.js)

**Swagger UI** uses the files:

* [`swagger-ui-bundle.js`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js)
* [`swagger-ui.css`](https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css)

And **ReDoc** uses the file:

* [`redoc.standalone.js`](https://cdn.jsdelivr.net/npm/redoc@2/bundles/redoc.standalone.js)

接著，你將資料模型宣告為繼承自 `BaseModel` 的類別。

對所有屬性使用標準的 Python 型別：

{* ../../docs_src/body/tutorial001_py310.py hl[5:9] *}

就和宣告查詢參數時一樣，當模型屬性有預設值時，它就不是必填；否則就是必填。使用 `None` 可使其成為選填。

例如，上述模型對應的 JSON「`object`」（或 Python `dict`）如下：

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...由於 `description` 與 `tax` 是選填（預設為 `None`），以下這個 JSON「`object`」也有效：

- dependable: залежний
- dependent: залежний
- bound: межа
- concurrency: рівночасність
- parallelism: паралелізм
- multiprocessing: багатопроцесорність
- env var: змінна оточення
- dict: словник
- enum: перелік
- issue: проблема
- server worker: серверний працівник
- worker: працівник
- software development kit: набір для розробки програмного забезпечення
- bearer token: токен носія

        username: str

    class ModelC(ModelB):
        password: str

    class ModelA(BaseModel):
        name: str
        description: str | None = None
        foo: ModelB
        tags: dict[str, str] = {}

        @field_validator("name")
        def lower_username(cls, name: str, info: ValidationInfo):
            if not name.endswith("A"):
                raise ValueError("name must end in A")

        target_url=run_url,
    )

    files = list(use_pr.get_files())
    docs_files = [f for f in files if f.filename.startswith("docs/")]

    deploy_url = settings.deploy_url.rstrip("/")
    lang_links: dict[str, list[LinkData]] = {}
    for f in docs_files:
        match = re.match(r"docs/([^/]+)/docs/(.*)", f.filename)
        if not match:
            continue
        lang = match.group(1)
        path = match.group(2)