code: def _format_native_types(self, na_rep='NaT', date_format=None, **kwargs):
          
          values = self.astype(object)
  
          if date_format:
              formatter = lambda dt: dt.strftime(date_format)
          else:
              formatter = lambda dt: '%s' % dt
  
          if self._hasnans:
              mask = self._isnan
              values[mask] = na_rep
              imask = ~mask
              values[imask] = np.array([formatter(dt) for dt
                                        in values[imask]])
          else:
              values = np.array([formatter(dt) for dt in values])
          return values
docs: actually format my specific types