def get_guess() -> str:
    """Get a letter from the user.

    Returns:
        str: Return the validated letter.
    """
    while True:
        user_input = input("Please enter a letter: ")
        if not isinstance(user_input, str):
            print("Please enter a letter between a and z")
            continue
        if len(user_input) != 1:
            print("Please enter one letter")
            continue
        if not user_input.isascii():
            print("Please enter a letter between a and z")
            continue
        return user_input.lower()