atoti.ExternalColumn#

`data_type`	The type of the elements in the column.
`isin`	Return a condition evaluating to `True` for elements of this column included in the given elements, and evaluating to `False` elsewhere.
`isnull`	Return a condition evaluating to `True` where this container evaluates to `None`, and evaluating to `False` elsewhere.
`name`	The name of the column.