[Python-3000] optimizing [x]range

[Greg Ewing]

skip at pobox.com wrote:
> Given that I find the cascading comparisons clearer I see no reason
> to optimize the "in range(...)" case.

The sort of thing I have in mind is where I have a sequence
that I want to frequently iterate over the indices of, so
I do

   r = xrange(len(myseq))

so I can write

   for i in r:
     ...

Having done that, if I want to test whether some index j
is within the range of indices for this sequence, it
seems natural to write

   if j in r:
     ...

Given the context, I think this is a very Obvious Way To
Do It, and it's surprising that it isn't as efficient as it
looks like it should be.

--
Greg