Asp Forum - Is it possible to use re2 from Python?

_wolf

3/14/2010 3:58:00 PM

i just discovered http://code.google..., a promising library
that uses a long-neglected way (Thompson NFA) to implement a regular
expression engine that can be orders of magnitudes faster than the
available engines of awk, Perl, or Python.

so i downloaded the code and did the usual sudo make install thing.
however, that action had seemingly done little more than adding /usr/
local/include/re2/re2.h to my system. there seemed to be some `*.a
file in addition, but then what is it with this *.a extension?

i would like to use re2 from Python (preferrably Python 3.1) and was
excited to see files like make_unicode_groups.py in the distro (maybe
just used during the build process?). those however were not deployed
on my machine.

how can i use re2 from Python?

(this message appeared before under
http://stackoverflow.com/questions/2439345/is-it-possible-to-use-re2-f...
and, even earlier, http://groups.google.com/group/re2-dev/t/59b783...)

7 Answers

Kev

3/14/2010 6:19:00 PM

On Sun, 14 Mar 2010 08:57:36 -0700, _wolf wrote:

>
> how can i use re2 from Python?
>

Hello Wolf,

There's a recent thread about this on the python-dev list,
Unfortunately it seems to suggest that there are no Python
bindings at present.

Cheers,

Kev

Vlastimil Brom

3/14/2010 8:50:00 PM

2010/3/14 _wolf <wolfgang.lipp@gmail.com>:
>...
> i would like to use re2 from Python (preferrably Python 3.1) and was
> excited to see files like make_unicode_groups.py in the distro (maybe
> just used during the build process?). those however were not deployed
> on my machine.
>...
>

If you would need a re engine with features like unicode rangees,
script, and character properties classes and many others, you may try
the proposed implementation of the re library currently available in
python issue tracker:
http://bugs.python.org...
I am personally more than satisfied with this development version
sofar, however, as some new feature like unlimited lookarounds etc.
suggest, it is a classic backtracking engine (as opposed to re2, if
you need this very implementation).

hth
vbr

_wolf

3/14/2010 9:40:00 PM

i am afraid that thread goes straight perpendicular to what re2 is
supposed to be, or do. my suggestion for these folks would be to
create a new, clean interface to stop the violence that comes with the
Python ``re`` interface, and open the thing up so one can plug in
``re`` implementations as are needed. when i absolutely need a
feature, i can always go to the slower machine; simpler regular
expressions could be dealt with more efficiently.

_wolf

3/14/2010 9:41:00 PM

> There's a recent thread about this on the python-dev list,

pointers? i searched but didn’t find anything.

Kev

3/15/2010 7:50:00 AM

On Sun, 14 Mar 2010 14:40:34 -0700, _wolf wrote:

>> There's a recent thread about this on the python-dev list,
>
> pointers? i searched but didnâ??t find anything.

http://mail.python.org/pipermail/python-dev/2010-March/0...

_wolf

3/24/2010 5:44:00 PM

yes we can! http://github.com/face...

as pointed out by http://stackoverflow.com/users/219162/daniel...

now gotta go and try it out.

Tim Wintle

3/25/2010 9:34:00 AM

On Wed, 2010-03-24 at 10:44 -0700, _wolf wrote:
> yes we can! http://github.com/face...

I had made a thin wrapper experiment with here - looks like the version
he's shipped is relatively complete and compatible with the re module
though.

I'll be interested in seeing how well it performs - The wrapper I had
been experimenting with ended up far slower than the re module for
simple expressions - and the fastest codepaths in RE2 seem to be ones
that are incompatible with the API we're used to using in the re module.

Tim

comp.lang.python

Is it possible to use re2 from Python?

_wolf

Kev

Vlastimil Brom

_wolf

_wolf

Kev

_wolf

Tim Wintle

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