An easy way to do it:
from mutagen.easyid3 import EasyID3
audio = EasyID3(mp3_filename_import)
audio['title'] = "Title"
audio['artist'] = "Artist"
audio['album'] = "Album"
audio['composer'] = "" # empty
audio.save()
If the tags don't appear, then change the last line to:
audio.save(v2_version=3)
