#!/usr/bin/env python3
"""Convert a distance matrix into the Phylip format (lower triangle) which can
then be parsed by ClearCut.

Usage:
    dm_to_phylip.py input.dm > output.phy
"""

from sys import argv
from os import popen


def main():
    # get dimension of distance matrix
    n = int(popen('cat %s | wc -l' % argv[1]).read().rstrip()) - 1
    print(str(n))

    # print lower triangle only
    i = 1
    with open(argv[1], 'r') as f:
        next(f)
        for line in f:
            print('\t'.join(line.rstrip('\r\n').split('\t')[:i]))
            i += 1


if __name__ == '__main__':
    main()