def randomfasta_parser(subparsers):
    """
    Parser for the randomfasta tool.
    """
    parser = subparsers.add_parser('randomfasta', help=
        'create a random FASTA file', description=
        'Create a FASTA file with random nucleotide sequences.')
    parser.add_argument('seq_length', type=int, help='random sequence length')
    parser.add_argument('seq_num', type=int, help='random sequence number')
    parser.add_argument('output', help='output filename')
