Python yes/no while loop?

I'm trying to end a program with a question that asks a user if they'd like to begin the program again.

However, I'm not sure how to use a while loop at the beginning. Right now i have

another='Y'

while another == 'Y' or another == 'y':

[CODE]

another=str(input("Would you like to start from the beginning? Y/N: "))

I know it's wrong. Im not sure how to do it correctly