Fredrik Lundh wrote: > [EMAIL PROTECTED] wrote: > > > I thought the xrange was preferred? for x in xrange(length): > > preferred by premature optimization freaks, perhaps.
There's a huge difference between not being profligate with resources and premature optimisation. In the case of the idiom "for i in range(x):..." there absolutely no utility whatsoever in creating and recording the list of objects. Unless it makes a difference to code structure or maintainability, I think that not creating stacks of objects you don't need is basic code hygiene and not freakish premature optimisation. > in practice, if the > range is reasonably small and you're going to loop over all the integers, > it doesn't really matter. This is true, but getting into habits that don't matter most of the time, but have an performance and stability impact some of the time, is worth discouraging. > (the range form creates a list and N integers up front; the xrange form > creates an iterator object up front and N integers while you're looping. > what's faster depends on what Python version you're using, and some- > times also on the phase of the moon) Using range() is only faster on lists so small then the cost is tiny anyway. On any substantial loop it is quite a bit slower and has been since python 2.3 Nicko -- http://mail.python.org/mailman/listinfo/python-list
