question about xrange performance

[mmanns at gmx.net]

On Fri, 17 Apr 2009 23:40:32 -0700 (PDT)
bearophileHUGS at lycos.com wrote:

> Paul McGuire:
> 
> >xrange is not really intended for "in" testing,<
> 
> Let's add the semantic of a good and fast "in" to xrange (and to the
> range of Python3). It hurts no one, allows for a natural idiom
> (especially when you have a stride you don't want to re-invent the
> logic of skipping absent numbers), and it's readable.

A fast "in" to xrange would be great.
Why was it taken away?