This Code is written in python 2.7. So, You have to Download Python 2.7 form the website. In this code, pycrypto Module is required for calculating some functions like keys,encode,decode and many more.
https://www.python.org/download/releases/2.7/
Download pycrpto module according to your system configuration and python version. http://www.voidspace.org.uk/python/modules.shtml#pycrypto