"app" its intended to run in the comand line by running scripterp.py
the other .py scripts are: minierp.py = it stores all the functions and classes that are called in scripterp.py data.py = it stores the data under the form of dictionaries - no data base was used for the intent to keep the project simple.
the "app" runs well, and calculates everthing as shown in scripterp.py menus. the emphasis was to put in practice as much as I could in a project that will not pass 7 days (cca 1-2 h / day), not on looks, as you may see. Tabulate its the prettiest thing here :) .