> if type(x) == int: # check its an integer
i also understand that it's "isinstance(x, int)" should be used instead of the above or "if type(x) is int" but i'm running a blank as to why at this exact moment... perhaps it's an all-C function? however, all of these comparisons are only good if 'x' represents the object of desire. if it's output from raw_input() [in 2.x] or input() [in 3.x], it won't do any good because 'x' would still be a str. so before converting to an int, i would go with the isdigit() method, perhaps x.strip().isdigit() because you don't want to be messed up by a user who may have inadvertently typed one or more spaces before or after the number. hope this helps! -- wesley - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - "Core Python Programming", Prentice Hall, (c)2007,2001 "Python Fundamentals", Prentice Hall, (c)2009 http://corepython.com wesley.j.chun :: wescpy-at-gmail.com python training and technical consulting cyberweb.consulting : silicon valley, ca http://cyberwebconsulting.com _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor