A function that works for both, Python 2.x and Python 3.x.
       It asks the user for input and returns it as a string.

def input_int_default(question="", default=0):
    """A function that works for both, Python 2.x and Python 3.x.
       It asks the user for input and returns it as a string.
    """
    answer = input_string(question)
    if answer == "" or answer == "yes":
        return default
    else:
        return int(answer)