def clean(self, value, row=None, *args, **kwargs):
return value<EOL>
Returns an appropriate Python object for an imported value.

For example, if you import a value from a spreadsheet,
:meth:`~import_export.widgets.Widget.clean` handles conversion
of this value into the corresponding Python object.

Numbers or dates can be *cleaned* to their respective data types and
don't have to be imported as Strings.