read_and_write.py

from argparse import ArgumentParser

parser = ArgumentParser()
parser.add_argument('input_file',    type=str)
parser.add_argument('output_file',   type=str)

args = parser.parse_args()

import icartt

ict = icartt.Dataset(args.input_file)
ict.splitChar = ", "

with open(args.output_file, 'w') as f:
    ict.write(f)