获取歌曲, 对外统一接口

def get_song(self, netease=False):
        """
        获取歌曲, 对外统一接口
        """
        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