def blast(args):
    """
    %prog blast btabfile

    Convert to BLAST -m8 format.
    """
    p = OptionParser(blast.__doc__)

    opts, args = p.parse_args(args)

    if len(args) != 1:
        sys.exit(not p.print_help())

    btabfile, = args
    btab = Btab(btabfile)
    for b in btab:
        print(b.blastline)
%prog blast btabfile

    Convert to BLAST -m8 format.