A first full-fleged program :

-Functions to :

• Create a cypher(code) as a list of tuples, by matching a printable character to a random number
• Encypt a string with code (encode(string, code))
• Decrypt a string with code (decode(string, code))
• Save/overwrite code in a pickle file (save_code(code))
• Retrieve code from the pickle file (load_code())

-A simple user interface as main loop