• What, Why?
  The book refactoring: improving the design of existing code only has Java version codes, I am not a fun of Java but interested in Python, so I made the Python version demos of the book as an exercise.

• 这是干啥和为啥？
  《重构:改善既有代码的设计》的例子都是Java版的，除了偶尔做些Android原型开发和概念验证 偶不怎么碰Java也不是非常喜欢碰，相对更喜欢Python和其他一些语言，所以边读变写python例子作为练习。

The book is (https://book.douban.com/subject/27193155)

The book is (https://book.douban.com/subject/26791753)