code: def _prepare_data(self):
          
          self._extract_genes()
          self._extract_total_number_of_chars()
          self._extract_number_of_taxa()
          self._extract_reading_frames()
  
          Data = namedtuple('Data', ['gene_codes', 'number_taxa', 'number_chars',
                                     'seq_records', 'gene_codes_and_lengths',
                                     'reading_frames'])
          self.data = Data(self.gene_codes, self.number_taxa, self.number_chars,
                           self.seq_records, self._gene_codes_and_lengths,
                           self.reading_frames)
docs: Creates named tuple with info needed to create a dataset.
  
          :return: named tuple