[2010-01] an old example of how __slots__ works

slotDemo.py

#!/usr/bin/env python
# encoding: utf-8
from __future__ import division, with_statement
import sys, os

class StrictPerson(object):
	__slots__ = ["first", "last", "age"]
	
	def __str__(self):
		return "%s %s (%s)" % (self.first, self.last, self.age)

def main():
	me = StrictPerson()
	
	try:
		print me
	except AttributeError:
		"Because I haven't set any of the required attributes, obviously."
	
	me.first = "Jeremy"
	me.last = "Banks"
	me.age = 19
	
	print me
	
	try
		me.likesPotatoes = True
	except AttributeError:
		"Because I haven't made a slot for that attribute!"

if __name__ == "__main__": sys.exit(main())