=== "Python 3.8+"

    ```Python hl_lines="7-11"
    {!> ../../../docs_src/body/tutorial001.py!}
    ```

The same as when declaring query parameters, when a model attribute has a default value, it is not required. Otherwise, it is required. Use `None` to make it just optional.

For example, this model above declares a JSON "`object`" (or Python `dict`) like:

```JSON
{
    "name": "Foo",
    "description": "An optional description",