parent_dir
____sub_dir01
____ ____music01.mp3
____ ____music02.mp3
____ ____musicxx.mp3
____ ____...
____sub_dir02
____sub_dirxx...
____sub_dir01.m3u8
____sub_dir02.m3u8
____sub_dirxx.m3u8
____...
The folder contains all the files.
Generated m3u8lists will be here, which are named after names of the sub_dir.
Adequate classified ones.
Files will be neglected, except .mp3 and .flac.
Do not put files in the parent_dir, except .py and .m3u8.