Working on writing a program that will encode a file using the caesar cipher method.

Problem using python 3

Write a program to encode an ASCII text file using a caesar cipher.

Program needs to ask for input for the shift value (from 1-26) and the name of a text file, and write the encoded text to ciphertext.txt. Encode everything, including punctuation and whitespace, using Unicode/ASCII values.

Also if there is an explantion on how to decode the cipher version that would help as well.

Thank you