Instructions: Program #2: Sum the digits in a String named sumDigits.py

need the code to copy for python. and need explanation of what the program does. (also please provide a screenshot of the code) Write a program that ask the user to enter four single-digit numbers with nothing separating them. The program will display the sum of the four numbers entered. Use comments to explain what the program does. Use the information below to verify that your application is calculating correctly: If the user enters 1366 the output would be 16 which is the sum of 1+3+6+6.