> > how about custom constant type? > > Does python provide? > No. Python tries to be as "light" as possible. There is a convention > amongst Python programmers to use upper case names to represent > constants, e.g. RED = 3.
another aspect of Python numbers that make them "constant" is that all numeric types are immutable, meaning you cannot change their values anyway. the idiom that Bob and Alan described is mostly for the programmer. you can, of course, reassign that variable to another number (which is also immutable), and Python won't stop you. i have used tuples/lists and dicts as a proxy for enum-type functionality, and they work just fine. also, do not get confused between all this and the enumerate() built-in function. all that does is for a sequence, return both an index and the corresponding sequence element so that folks stop doing stuff like "for i in range(len(seq))". hope this helps! -- wesley - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - "Core Python Programming", Prentice Hall, (c)2007,2001 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