[Python-ideas] re.compile_lazy - on first use compiled regexes

[Ezio Melotti]

On Sat, Mar 23, 2013 at 2:52 PM, M.-A. Lemburg <mal at egenix.com> wrote:
> On 23.03.2013 13:43, Ronny Pfannschmidt wrote:
>>
>>> Wouldn't it make sense to add a way to pickle or marshal compiled REs ?
>>>
>>> The precompiled REs could then be loaded directly from the
>>> pickle, avoiding the compiling overhead on startup.
>>>
>>
>> as far as i can tell that would need regex as part of the syntax to make sense fort use in modules
>> i dont think such a change would be accepted and i dont even what to deal with the potential
>> bikeshedding for such an integration
>
> I wasn't thinking of making it part of the Python byte-code.
>
> It would suffice to add pickle/marshal support for the
> compiled RE code. This could then be loaded from a string
> embedded in the module code on startup.
>
> E.g.
> # rx = re.compile('.*')
> rx = pickle.loads('asdfsadfasdf')
>

According to http://bugs.python.org/issue11454#msg170697, this would
be twice as slow.

Best Regards,
Ezio Melotti

> It would also be possible to seed the re module cache with
> such pickle.loads, perhaps compiled at Python build time.
> This would avoid having to change code in the stdlib to
> load pickles.
>
> --
> Marc-Andre Lemburg
> eGenix.com