code: def load_file(self, sequence):
          
          try:
              if sequence.filetype_ext == 'npy':
                  sequence.series = sequence.adjust_series(
                      *self._load_npy(sequence))
              elif sequence.filetype_ext == 'asc':
                  sequence.series = sequence.adjust_series(
                      *self._load_asc(sequence))
              elif sequence.filetype_ext == 'nc':
                  self._load_nc(sequence)
          except BaseException:
              objecttools.augment_excmessage(
                  'While trying to load the external data of sequence %s'
                  % objecttools.devicephrase(sequence))
docs: Load data from an "external" data file an pass it to
          the given |IOSequence|.