old_contents: # -*- coding: utf-8 -*-
  import os
  from os.path import isfile, join
  
  __author__ = 'ElvisJia'
  
  
  class MusicLoader(object):
  
  	@staticmethod
  	def load_music_lists(music_path):
  		music_list_dir = os.listdir(music_path)
  		return [MusicLoader.list_all_files(music_list) for music_list in music_list_dir]
  
  	@staticmethod
  	def list_all_files(path):
  		return [join(path, file) for file in path if isfile(join(path, file))]
  
  
new_contents: # -*- coding: utf-8 -*-
  from genericpath import isdir
  import os
  from os.path import isfile, join
  
  __author__ = 'ElvisJia'
  
  
  class MusicLoader(object):
  
  	@staticmethod
  	def load_music_lists(music_path):
  		music_list_dir = os.listdir(music_path)
  		return [MusicLoader.list_all_files(music_list) for music_list in music_list_dir if isdir(music_list)]
  
  	@staticmethod
  	def list_all_files(path):
  		return [join(path, file) for file in os.listdir(path) if isfile(join(path, file))]
  
  
subject: fix load files error