Check out what is Python package

It's been a while I learn python and today, I would like to check out what is python package. These two reference give python package definition pretty clear.

Packages are a way of structuring Python's module namespace by using "dotted module names". For example, the module name ‘A.B’ designates a submodule named ‘B’ in a package named ‘A’. Just like the use of modules saves the authors of different modules from having to worry about each other's global variable names, the use of dotted module names saves the authors of multi-module packages like NumPy or the Python Imaging Library from having to worry about each other's module names. 

and from learn python org

Packages are namespaces which contain multiple packages and modules themselves. They are simply directories, but with a twist. 

Each package in Python is a directory which MUST contain a special file called __init__.py. This file can be empty, and it indicates that the directory it contains is a Python package, so it can be imported the same way a module can be imported. 

If you come from java background, essentially java package are directories until you create a class. In python, for that directory, you need to create a unique empty file call __init__.py which denote this is a python package.

So something like

router_statistics
    __init__.py
    routerStats.py
    test
        __init__.py
        router_stats_test.py

The above file structure is from github project.We have a python package router_statistics with a module routerStats.py. Then we have a test python package and a test module router_stats_test.py.

Pretty neat :) That's all for this light learning experience.