py_enter_month.py

#!/usr/bin/python

class BadUserError(Exception):
    pass

def get_integer(retrieve,question,attempts=3):
    while attempts > 0:
        num = retrieve(question)
        try:
            return int(num)
        except ValueError:
            print "Opps, you must enter a number!"
        attempts -= 1
    raise BadUserError("Too many incorrect attempts!")

s = get_integer(raw_input,"Enter a number between 1 and 31. 99 to quit : ")

while (s != 99):
    if s < 1 or s < 31:
        print "Opps, You entered number", s
        s = get_integer(raw_input,"Enter a number between 1 and 31. 99 to quit : ")
    else:
        print "You entered number", s
        break