Python slot example

gistfile1.py

>>> class example(object):
	__slots__ = ["x", "y", "z"]

>>> example = example()
>>> example.x = 0
>>> example.y = '0'
>>> example.z = 'Null'
>>> example.a = 0
Traceback (most recent call last):
  File "", line 1, in ?
    example.a = 0
AttributeError: 'example' object has no attribute 'a'
>>>

Related post: http://lloc.de/slots-in-php-wie-in-python.html