Readability:

Design and implement a program in Python which does the following
Prompts a user to enter a test score (out of 100)
Prints the letter grade for the score, i.e. A(90 – 100), B(from 80 and up, but less than 90 ), C( from 70 and up, but less than 80), D( from 60 and up, but less than 70), F(from 0 and up, but less than 60 )
Store the numeric score in a list
Ask the user if s/he wants to add another entry
If the user chooses to end the session, print the entire list of numbers entered
Otherwise prompt the user to enter the next score
Error handling:
If the user enters a non-numeric value ask the user to enter a numeric value (loat and integer values)
If the user enters a value out of range, ask the user to try again
If the user chooses to end the session, print all the scores that were entered.
Readability:
You must use comments in your code
You must use meaningful variable names