Normalize ID3 tags from filename

cleantags.py

#!/usr/bin/env python3
import re
import os
import sys
import mutagen.id3

def main(filepath):
    print(filepath)

    # Save original mtime
    stat = os.stat(filepath)

    # Parse artist/title from filename
    filename = os.path.basename(filepath)
    match = re.match("(.*) - (.*).mp3", filename)
    if not match:
        raise RuntimeError("Filename not in `<artist> - <title>.mp3` format")
    artist = match.group(1)
    title = match.group(2)

    # Load ID3 tags from file
    try:
        id3 = mutagen.id3.ID3(filepath)
    except mutagen.id3.ID3NoHeaderError:
        id3 = mutagen.id3.ID3()

    # Clear all current ID3 tags
    id3.delete(filepath)

    # Add artist/title tags
    id3.add(mutagen.id3.TPE1(encoding=mutagen.id3.Encoding.UTF8, text=[artist]))
    id3.add(mutagen.id3.TIT2(encoding=mutagen.id3.Encoding.UTF8, text=[title]))

    # Write ID3 tags to file, deleting ID3v1 tags
    id3.save(filepath, v1=0)

    # Restore original mtime
    os.utime(filepath, times=(stat.st_atime, stat.st_mtime))


if __name__ == "__main__":
    if len(sys.argv) > 1:
        for arg in sys.argv[1:]:
            main(arg)
    else:
        for f in os.listdir():
            if f.endswith(".mp3"):
                main(f)