csv2xlsx

#!/usr/bin/env python

import sys
import csv
from argparse import ArgumentParser
from pathlib import Path

from openpyxl import Workbook

exts = {
    '.tsv': '\t',
    '.csv': ',',
}

parser = ArgumentParser()
parser.add_argument('output', type=Path)
parser.add_argument('inputs', nargs='+', type=Path)
parser.add_argument('--delimiter', '-d', help=f'Specify if your files don’t have extensions of {set(exts)!r}.')
args = parser.parse_args()

if args.output.is_file():
    print(f'Output file {args.output} already exists.', file=sys.stderr)
    sys.exit(1)

wb = Workbook()
for f, path in enumerate(args.inputs):
    title = path.with_suffix('').name
    if f == 0:
        sheet = wb.active
        sheet.title = title
    else:
        sheet = wb.create_sheet(title)
    
    with path.open() as file:
        delim = exts.get(path.suffix, args.delimiter)
        if delim is None:
            print(f'Input file {path} has no known extension and -d is not set.', file=sys.stderr)
            sys.exit(1)
        reader = csv.reader(file, delimiter=delim)
        for r, row in enumerate(reader, 1):
            for c, cell in enumerate(row, 1):
                sheet.cell(row=r, column=c).value = cell
wb.save(args.output)