Traceback (most recent call last):
File "E:/Python 程序/xue E.py", line 53, in <module>
(music_id_set,singer_name_all) = get_music_ids_by_singer_id(5781)
File "E:/Python 程序/xue E.py", line 25, in get_music_ids_by_singer_id
bs_obj = BeautifulSoup(r,'lxml')
File "E:\Python 3.6\lib\bs4\__init__.py", line 165, in __init__
% ",".join(features))
bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?