It‘s also worth noting that you can use * and ** when calling functions as well. This is a shortcut that allows you to pass multiple arguments to a function directly using either a list/tuple or a dictionary. For example, if you have the following function:
When you use two asterisks you usually call them **kwargs for keyword arguments.
ref: http://stackoverflow.com/questions/36901/what-does-double-star-and-star-do-for-parameters
http://stackoverflow.com/questions/3394835/args-and-kwargs
difference bewteen *args and **args in python?
原文：http://www.cnblogs.com/pinganzi/p/6203459.html