efficiency of range() and xrange() in for loops

[mensanator at aol.com]

Todd wrote:
> Steve R. Hastings wrote:
> > When you compile the expression
> >
> >     for i in range(1000):
> >         pass
> >
> > does Python make an iterator for range(), and then generate the values
> > on the fly?  Or does Python actually allocate the list [0, 1, 2, ..., 999]
> > and then step through it?
>
> I ran an experiment on this a while back.  I thought it generated a
> list.  But the results turned out to be surprising.  Take this with a
> grain of salt.  I'm not completely sure I did what I meant to do.  But
> it looks like however you do it, it works out about the same.
>
> http://www.signalsguru.net/articles/pyloops/pyloops.html

Didn't it occur to you to also check memory usage?

I learned about xrange the hard way, when my range ate up all
available memory.