[Python-Dev] re performance

[MRAB]

On 2017-01-26 21:46, Sven R. Kunze wrote:
> On 26.01.2017 22:33, Vlastimil Brom wrote:
>> Hi,
>> I can't speak about the details of mrab's implementation, but using
>> regex, I get the resulting match instantly: [...]
>
> Nice! I focused on the stdlib re module as this is mainly used by other
> frameworks (like Django).
>
>> (I personally prefer to use regex for other advantages, than this
>> artificial case, but it certainly doesn't hurt to have better
>> performance here too:)
>
> Me, too.
>
> So, it seems as if regex already uses a better algorithm although I
> couldn't find any reference to any regex theoretical framework like dfa,
> nfa, thompson multiple-state simulation or something.
>
It still uses backtracking, like in the re module.