example, a shift value of $1$ would convert the input abcd to bcde $-$ each letter is replaced with the letter $1$ place further in the alphabet. Letters at the end of the alphabet are replaced with letters at the start, so a shift value of $1$ would replace $z$ with $a.$

The shift cipher is also known as the Caesar Cipher.

Learning Objectives

he goal of this assignment is to demonstrate understanding of the following topics in Python:

Lists

Nested Loops

Handling User Input

Functions, Parameters, Arguments, and Return

The Assignment

Write your program in a file named

homework$5.$py$.$ This should be a complete Python program consisting of the following elements:

A get$\_$shift$()$ function

A choose$\_$option$()$ function

A get message$()$ function

A create$\_$key$($shift$)$ function

An encode$($message$,$ key$)$ function

A decode$($message$,$ key$)$ function