The original .py file will run completely fine in jupyter notebook. If you are trying to run it in command prompt,make sure you add the necessary path statement at the start.
It is a python program which encrypts and decrypts messages using the vigenere cipher. Looking for a good mini project for python? Use this source code and create your own version of the message encrypt-decrypt program. This program uses tkinter and hence will run only on devices that support the tkinter module.