From: "candide" <candide@free.invalid> Subject: Regular expression : non capturing groups are faster ?
Excerpt from the Regular Expression HOWTO (http://docs.python.org/howto/regex.html#non-capturing-and-named-groups) : ----------------------------------------------- It should be mentioned that there’s no performance difference in searching between capturing and non-capturing groups; neither form is any faster than the other. ----------------------------------------------- Now from the Perl Regular Expression tutorial (http://perldoc.perl.org/perlretut.html#Non-capturing-groupings) : ----------------------------------------------- Because there is no extraction, non-capturing groupings are faster than capturing groupings. ----------------------------------------------- The second assertion sounds more likely. It seems very odd that Python and Perl implementations are divergent on this point. Any opinion ? -- ** At least in Perl's case, it is true. I tested and using (?:...) is much faster than (). Of course, it takes a few seconds for dozen million matches... Octavian -- http://mail.python.org/mailman/listinfo/python-list
