Small tool to rename audio files in a directory

mp3_rename.py

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

import os
import stat
import re
import argparse


parser = argparse.ArgumentParser()
parser.add_argument(
    "-t", "--test",
    help   = "test run, only prints converted filenames",
    action = "store_true")
parser.add_argument(
    "-e", "--end",
    help   = "remove string after - from end of filenames",
    action = "store_true")
parser.add_argument(
    "-r", "--remove",
    help = "remove REMOVE (quoted) string from filenames")
parser.add_argument(
    "-b", "--begin",
    help = "remove BEGIN chars from beginning of filenames")
parser.add_argument(
    "-a", "--add",
    help = "add ADD chars before beginning of filenames")
args = parser.parse_args()

replacer = (("&", "and"), ("!", ""),  ("?", ""), ("ü", "ue"), ("ä", "ae"),
            (" ", "_"), (",", ""))

filelist = os.listdir()
filelist.sort()

for name in filelist:
    if name.lower().endswith((".mp3", ".flac", ".ogg", ".m4a")):
        if(args.begin):
            new_name = name[int(args.begin):]
        else:
            new_name = name
        if(args.remove):
            new_name = new_name.replace(args.remove, "")
        new_name = new_name.casefold()
        for i, j in replacer:
            new_name = new_name.replace(i, j)
        if(args.end):
            new_name = re.sub(r"^(.+)(-.+)(\..+)", r"\1\3", new_name)
        new_name = re.sub(r"^([0-9]+)_+([\(a-z0-9])", r"\1_-_\2", new_name)
        new_name = re.sub(r"^([0-9]+)_*-_*([\(a-z0-9])", r"\1_-_\2", new_name)
        new_name = re.sub(r"^([0-9]+)_*\.+_*([\(a-z0-9])", r"\1_-_\2", new_name)
        new_name = re.sub(r"^(cd[0-9]+)_*-_*([0-9]+)_*-*_*([\(a-z0-9])",
                          r"\1_-_\2_-_\3", new_name)
        if(args.add):
            new_name = args.add + new_name
        if args.test:
            print(name + " -> " + new_name)
        else:
            try:
                os.rename(name, new_name)
                os.chmod(new_name, stat.S_IROTH | stat.S_IRGRP |
                    stat.S_IRUSR | stat.S_IWUSR)
            except OSError:
                print("File I/O error")