practice:数据教科书

Archiving data and codes for textbooks 教材数据与代码 Data and codes for some excellent textbooks are public and shared in this repository. Some of them are purchased on some websites and some of them are shared by other data science learners like me. I wish it will help many learners like me. 一些优秀教材的数据与代码是公开的，并且分享于在这个仓库中，其中有些是从网上购买的，而有些则是一些像我一样的数据科学学习者分享出来的。 If you have data(or codes) for some books tha