On Thu, Sep 26, 2019 at 05:34:49PM +0200, Ján Tomko wrote:
On Thu, Sep 26, 2019 at 02:16:04PM +0100, Daniel P. Berrangé wrote:
On Thu, Sep 26, 2019 at 12:39:39PM +0200, Erik Skultety wrote:
On Tue, Sep 24, 2019 at 03:58:44PM +0100, Daniel P. Berrangé wrote: question 1) what's the benefit of compiling a regex and using it only once? Btw python does cache every pattern passed to re.match (and friends) so compilation IMO hardly ever makes sense unless you're doing 1000s of searches for the same
Some of the scripts here are run on the whole libvirt codebase so that is the case here. For example just removing the pre-compilation of regexes for comments from the spacing check script bumped the execution time from 6.5s to 7.4s
Sadly, the one script where pre-compilation matters the most is the one where separating them puts them far away from the usage to not fit on one screen.
I could do a little custom function that caches all regexes recache = {} def research(regex, line): global recache if regex not in recache: recache[regex] = re.compile(regex) return recache[regex].search(line) then the loop we can do a normal research(r'''some regex''', line) so we can get readability and full caching together. Probably not worth repeating this trick for every script, but certainly the whitespace script and a few others probably benefit. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|