code: def naturalize_person(self, string):
          suffixes = [
                      'Jr', 'Jr.', 'Sr', 'Sr.',
                      'I', 'II', 'III', 'IV', 'V',
                      ]
          suffixes = suffixes + [s.lower() for s in suffixes]
          particles = [
                      'Le', 'La',
                      'Von', 'Van',
                      'Du', 'De',
                      ]
          surname = ''
          names = ''
          suffix = ''
          sort_string = string
          parts = string.split(' ')
          if parts[-1] in suffixes:
              suffix = parts[-1]
              parts = parts[0:-1]
              sort_string = ' '.join(parts)
          if len(parts) > 1:
              if parts[-2] in particles:
                  parts = parts[0:-2] + [ ' '.join(parts[-2:]) ]
              sort_string = '{}, {}'.format(parts[-1], ' '.join(parts[:-1]))
          if suffix:
              sort_string = '{} {}'.format(sort_string, suffix)
          sort_string = self._naturalize_numbers(sort_string)
          return sort_string