Steve Juranich wrote: > IMHO, __slots__ is unpythonic. Many others have stated so on the > list. That's why it's great that you're free to ignore that variable. > I suggest that you do so (as I have chosen to do). I'm sure that > there are situations where you *MUST* have this kind of capability, > but I haven't bumped into them yet.
In general, I would agree that __slots__ is unpythonic. And I can state categorically that there is *no* situation where __slots__ is actually required - everything semantically that __slots__ does (including the incidental restriction of attributes) can be done via other mechanisms. That being said ... there *are* use cases for __slots__ (otherwise it would not exist ;) Specifically, __slots__ is a memory and performance optimisation. One you should almost never use. In my self.super recipe <http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/286195>, use of __slots__ made a measurable difference in performance - and since my aim was to replace `super(cls, self)` with `self.super`, getting as close to the performance of `super(cls, self)` was important. Eventually of course, I achieved my best results using Pyrex and on-the-fly bytecode modification ... interestingly, the fastest approach I could find with Python (excluding the bytecode modifications) was slightly different to the fastest approach in Pyrex. Tim Delaney -- http://mail.python.org/mailman/listinfo/python-list
