look-behind fixed width issue (package re)

[Peng Yu]

> Most probably a backport to Python 2.6 or even 2.5 under a different
> module name like re_ng wouldn't be too difficult to do for anybody that
> needs the new functionality and knows a bit about building extension
> modules.

I did a google a search. But I don't find any document that describe
it. Does it have almost the same functionality as the re package that
will be in Python 2.7? Where is the decumentation of it?

If I just need variable width look-behind, I just replace re with
re_ng on python 2.5 or 2.6, right? Is re_ng available on python 2.4?

Thanks,
Peng