"Support" MultiValue type from pydicom

[yarikoptic]

I was surprised to not find ImageType meta data field in aggregated metadata, and discovered that it is not provided by pydicom as list or tuple but as pydicom.multival.MultiValue which is used for a few fields in a sample DICOM I have tortured. IMHO should get the same treatment as list -- the distinctive feature for this class is assuring uniform data typing.

*(Pdb) pprint(dict([(f, (getattr(d, f), type(getattr(d, f)))) for f in d.dir() if not isinstance(getattr(d, f), (int, float, string_types, dcm.valuerep.DSfloat, dcm.valuerep.IS, dcm.valuerep.PersonName3, list, tuple))]))
{'ImageOrientationPatient': (['0', '1', '0', '0', '0', '-1'],
                             <class 'pydicom.multival.MultiValue'>),
 'ImagePositionPatient': (['-101.60000151396', '-140', '130'],
                          <class 'pydicom.multival.MultiValue'>),
 'ImageType': (['ORIGINAL', 'PRIMARY', 'M', 'ND', 'NORM'],
               <class 'pydicom.multival.MultiValue'>),
 'PixelSpacing': (['1.625', '1.625'], <class 'pydicom.multival.MultiValue'>)}

[yarikoptic]

heh heh - here is the actual reason:

$> python -c 'import dicom as dcm; print(issubclass(dcm.multival.MultiValue, list), dcm.__version__)'
(True, '0.9.9')

$> python -c 'import pydicom as dcm; print(issubclass(dcm.multival.MultiValue, list), dcm.__version__)'
(False, '1.0.2')