normalisename/normalisename.py

#!/usr/bin/env python3
from unidecode import unidecode
from os import rename
from os.path import basename, dirname
from os.path import join as joinpath
from argparse import ArgumentParser

parser = ArgumentParser(description='Eliminate funky stuff from filenames.')
parser.add_argument('--separator', '-s', type=str, nargs='?', default='_',
                    help='Set separator to use (to replace spaces with).')
parser.add_argument('files', type=str, nargs='+',
                    help='File(s) to normalise the name of (relative or absolute path).')

args = parser.parse_args()


# special characters that will not be removed
whitelist = {' ', '.', '-'}
whitelist.add(args.separator)

for path in args.files:
    dir = dirname(path)
    file = basename(path)
    rename(path,
           unidecode
           (
               joinpath
               (
                   dir,
                   ''.join(ch for ch in file.replace(' ', args.separator)
                           if ch.isalnum()
                           or ch in whitelist)
               )
           ))