"""
1. What is a python package?
Python has packages for directories and modules for files.
Directory (folder)

python packages v.s. directories
__init__.py  meta data


2. basic idea
We place similar modules in one package and different modules in different packages.

mywork> work-201115.py

mygames>
    game1>......
    game2>.....

mytools>
    tool1>
    tool2>

3. structure
multi-level
multi-package
"""

