code: def get_song(self, netease=False):
          
          song = self._playlist.get(True)
          self.hash_sid[song['sid']] = True  # 去重
          self.get_netease_song(song, netease)  # 判断是否网易320k
          self._playingsong = song
  
          return song
docs: 获取歌曲, 对外统一接口