music-dupl.py

#!/usr/bin/env python
from __future__ import print_function
import glob
import os

m4a_files = glob.glob('*/*/*.m4a')
mp3_files = glob.glob('*/*/*.mp3')

to_delete = list()
for m4a in m4a_files:
    test = m4a.replace('.m4a', '.mp3')
    if test in mp3_files:
        to_delete.append(m4a)

for m4a in to_delete:
    # print(m4a)
    os.unlink(m4a)