doing
https://www.cnblogs.com/cymwill/articles/8042377.html
https://www.cnblogs.com/printN/p/6924077.html
https://www.cnblogs.com/alanxu312/p/6938977.html
https://www.cnblogs.com/yufeihlf/p/6179547.html
https://www.cnblogs.com/emily-qin/p/7001277.html#4000512
http://www.iplaypy.com/module/os.html
https://www.cnblogs.com/hdk1993/p/8428720.html
https://www.cnblogs.com/cwp-bg/p/8465566.html
http://www.runoob.com/python3/python3-os-popen.html
https://www.cnblogs.com/jiangnanyanyuchen/p/8668921.html
https://www.cnblogs.com/paranoia/p/6178385.html
https://www.cnblogs.com/emily-qin/p/7001152.html
https://www.cnblogs.com/yufeihlf/p/6179547.html
https://www.cnblogs.com/ybjourney/p/4767726.html