replace.py

import re
import argparse

parser = argparse.ArgumentParser(
  description="Replace special characters line-by-line in a file with space and print or store result.")
parser.add_argument("-f", "--file", default=None, help="input file", required=True)
parser.add_argument("-o", "--out", default=None, help="output file to store result")
parser.add_argument("-c", "--char-set", default=1, help="""character sets 
1: [a-zA-Z0-9\u00c0-\u00ff.<>'_-],
2: optimized for English,
3: optimized for German
""")
parser.add_argument("-l", "--lower", action='store_true', help="make everything lower-case")

args = parser.parse_args()

char_set = int(args.char_set)
if char_set not in [1, 2, 3]:
    raise SystemExit(f'-c ${char_set} NOT YET SUPPORTED')

new_file = [] if args.out is not None else None

with open(args.file, "r") as fp:
    for line in fp:
        if char_set == 1:
            # replace everything with space except a-z A-Z À-ÿ . <> ' _ -
            line = re.sub(r"[^a-zA-Z0-9\u00c0-\u00ff.<>'_-]", ' ', line)
        elif char_set == 2:
            # English characters
            line = re.sub(r"[^a-zA-Z']", ' ', line)
        elif char_set == 3:
            # German characters
            line = re.sub(r"[']", '', line)
            line = re.sub(r"[^a-zA-ZÄÖÜäöüß]", ' ', line)
        if args.lower:
            line = line.lower()
        if args.out is None:
            print(line)
        else:
            new_file.append(line)

if new_file is not None:
    with open(args.out, 'w') as fp:
        for line in new_file:
            fp.write("%s\n" % line)