import string


def get_tvtk_name(vtk_name):
    """Converts a VTK class name to a TVTK class name.

    This function additionally converts any leading digits into a
    suitable string.

    For example:

      >>> get_tvtk_name('vtk3DSImporter')
      'ThreeDSImporter'
      >>> get_tvtk_name('vtkXMLDataReader')
      'XMLDataReader'

    """
    if vtk_name[:3] == 'vtk':
        name = vtk_name[3:]
        dig2name = {'1': 'One', '2': 'Two', '3': 'Three', '4': 'Four',
                    '5': 'Five', '6': 'Six', '7': 'Seven', '8': 'Eight',
                    '9': 'Nine', '0': 'Zero'}

        if name[0] in string.digits:
            return dig2name[name[0]] + name[1:]
        else:
            return name
    else:
        return vtk_name