import os

def main():
    for subdir, dirs, files in os.walk(dir):
        for file in files:
            if file.endswith(".mp3") or file.endswith(".m4a"):
                print(os.path.abspath(file))

music
--1.mp3
--2.mp3
--folder
----a.mp3
----b.mp3
----c.mp3
----d.m4a
----e.m4a

C:UsersUserDocumentspython_music1.mp3
C:UsersUserDocumentspython_music2.mp3
C:UsersUserDocumentspython_musica.mp3
C:UsersUserDocumentspython_musicb.mp3
C:UsersUserDocumentspython_musicc.mp3
C:UsersUserDocumentspython_musicd.m4a
C:UsersUserDocumentspython_musice.m4a

print(os.path.join(subdir, file))