# is_unset

<table class=".origin_table">
    <tr>
        <td style="text-align: left; border-style: hidden">*function*  of [dascore.core._spool_inventory](`dascore.core._spool_inventory`)</td>
        <td style="text-align: right; border-style: hidden">[source](https://github.com/DASDAE/dascore/blob/dev/dascore/core/_spool_inventory.py#L507-L516)</td>
    </tr>
</table>

:::{.padded_bottom_10pt}

:::{.def_block}


<b>is_unset</b>(<br>
    &nbsp;&nbsp;&nbsp;&nbsp;value
,<br>
)-> 'bool'


:::

:::
Return True when an attr holds no information.

NaN is how readers spell an unknown number, so a NaN placeholder is
filled rather than treated as a value which disagrees.