A program where it requires the user to ONLY type a Yes or No answer, otherwise repeat the whole question

Question

while True:

#SOME CODE...

    ch = input("\nWould you like to try again? Y/N: ").upper()

    if ch == 'Y':
        continue # continue the whole program
    elif:
        print("Thanks for using the program.")
        break # stops the program
    else:
        # repeats the Y or N question only; and prints 'Please input Y or N only'

I tried using continue statement on the else part but it loops back to the whole program and that's not what I want the program to do. Just only want the Y or N question to be looped if none of the conditions is met

Answer 1

You would use a second loop to validate the input before acting on one of the two valid inputs.

while True:
    # do something

    while True:
       ch = input("Try again").upper()
       if ch in ['YES', 'NO']:
           break
       print("Please enter yes or no")

    if ch == "NO":
        print("Thanks for using the program.")
        break

Answer 2

while True:

#SOME CODE...

    ch = input("\nWould you like to try again? Y/N: ").upper()

    if ch not in ['Y', 'N', 'YES', 'yes', 'no', 'NO']:
        pass
    else:
        print("Thanks for using the program.")
        break