docs: def find_total_sequence_length(fasta_file):
      """
      Totals up number of bases in a fasta file.
      :param fasta_file: Path to an uncompressed, fasta-formatted file.
      :return: Number of total bases in file, as an int.
      """
      total_length = 0
      for sequence in SeqIO.parse(fasta_file, 'fasta'):
          total_length += len(sequence.seq)
      return total_length