引用自：https://zhuanlan.zhihu.com/p/31675841
http://www.aleax.it/gdd_pydp.pdf
Design pattern categories:
- creational：Singleton ，factory，builder，prototype
factory：define an interface for creating an object, let subclass to decide which class to initialize.
builder：desperate the build and show case
prototype: easy for clone - structural：Proxy，
- behavioral
