addindexes.py

#! /usr/bin/env python3

import math
import itertools
import sys


def generate_dice_index_sequence(num_dices):
    digits = "123456"
    for index in itertools.product(digits, repeat=num_dices):
        s = ''.join(index)
        yield s


def get_file_lines_count(file):
    lines_count = sum(1 for lines in file)
    file.seek(0, 0)
    return lines_count


def calculate_index_size(count):
    return int(math.ceil(math.log(count, 6)))


def write_output(outputfile, collection):
    for (k, v) in collection:
        line = "{0}\t{1}".format(k, v)
        outputfile.write(line)


def try_open_file(filename):
    try:
        f = open(filename, "r")
    except IOError:
        print("unable to open file: {0}", filename)
        sys.exit(2)
    else:
        return f


def main(inputfilename):
    inputfile = try_open_file(filename)
    outputfilename = inputfilename + ".out"
    outputfile = open(outputfilename, "w")
    words_count = get_file_lines_count(inputfile)
    index_size = calculate_index_size(words_count)
    collection = zip(generate_dice_index_sequence(index_size), inputfile.readlines())
    write_output(outputfile, collection)
    outputfile.close()
    inputfile.close()


if __name__ == "__main__":
    if (len(sys.argv)) < 2:
        print("no input file name provided. exiting...")
        sys.exit(1)
    filename = sys.argv[1]
    main(filename)