mx-txt-viewtabular

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
DELIMITED (CSV/TSV) FILE VIEWER
James B. Pease
"""

import sys
import argparse
from pylib.mixcore import _LICENSE


def generate_argparser():
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.RawTextHelpFormatter,
        epilog=_LICENSE)
    parser.add_argument('datafile')
    parser.add_argument('--delim', default=','
                        help='field delimited, use "TAB" for tabs')
    parser.add_argument('--tsv',
                        action="store_true",
                        help="for tab-separated value")
    parser.add_argument('--nlines', type=int)
    parser.add_argument('--length', default=20,
                        type=int, help="field length")
    parser.add_argument('--no-header', action='store_true',
                        help="skip the header")
    return parser

def main(arguments=None):
    arguments = arguments if arguments is not None else sys.argv[1:]
    parser = generate_argparser()
    args = parser.parse_args(args=arguments)
    nlines = args.nlines + 0 if args.nlines is not None else None
    firstline = True
    if args.delim == 'TAB' or args.tsv is True:
        args.delim = '\t'
    with open(args.datafile, 'rt') as infile:
        for line in infile:
            arr = line.rstrip().split(args.delim)
            print("|".join("{}{}".format(
                x, " "*(args.length - len(x)))[:args.length] for x in arr))
            if firstline is True:
                firstline = False
                print("-"*((args.length + 1)*len(arr)))
            if nlines is not None:
                nlines -= 1
                if nlines == 0:
                    break
    return ''


if __name__ == '__main__':
    main()