How to encode and decode backward letter using ascii

Answer 1

khààlid Mohamud , it is not quite clear what you are asking for. Please provide us a sample with input data and how your output should look like. Thanks!

Answer 2

Do you mean between a character and its code number?
chr for int to char
ord for char to int
Python uses UTF8, not ascii. But for letters, numbers and common symbols it is the same