Create a pandas DataFrame from a Stoner.Data object.


In addition to transferring the numerical data, the DataFrame’s columns are set to a multi-level index of the Stoner.Data.column_headers and Stoner.Data.setas calues. A pandas DataFrame extension attribute, metadata is registered and is used to store the metada from the :py:class:1Stoner.Data` object. This pandas extension attribute is in fact a trivial subclass of the Stoner.core.typeHintedDict.

The inverse operation can be carried out simply by passing a DataFrame into the copnstructor of the Stoner.Data object.


**NotImplementedError** if pandas didn't import correctly.