Re: Why is regex so slow?

From	André Malo <ndparker@gmail.com>
Newsgroups	comp.lang.python
Subject	Re: Why is regex so slow?
Date	2013-06-18 22:13 +0200
Organization	TIMTOWTDI
Message-ID	<1532119.OxbuKqgHX2@news.perlig.de> (permalink)
References	(1 earlier) <CANc-5UyouN5EQw_GDecaAR+inyAB26g=e2pZ=zBuspXdmxJh+Q@mail.gmail.com> <B2AEBA54-6098-47D6-B7E0-77F0B7D8D722@panix.com> <mailman.3545.1371576060.3114.python-list@python.org> <kpq7q8$n9o$1@news.albasani.net> <2281418.s73s1ze9gg@news.perlig.de>

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* André Malo wrote:

> * Johannes Bauer wrote:
> 
>> The pre-check version is about 42% faster in my case (0.75 sec vs. 1.3
>> sec). Curious. This is Python 3.2.3 on Linux x86_64.
> 
> A lot of time is spent with dict lookups (timings at my box, Python 3.2.3)
> in your inner loop (1500000 times...)

[...]

Missed one basic timing BTW:

#!/usr/bin/python3
def main():
    for line in open('error.log'):
        pass
main()

runs ~ 0.53 s

nd
-- 
Already I've seen people (really!) write web URLs in the form:
http:\\some.site.somewhere
[...] How soon until greengrocers start writing "apples $1\pound"
or something?                           -- Joona I Palaste in clc

Thread

Why is regex so slow? roy@panix.com (Roy Smith) - 2013-06-18 12:45 -0400
  Re: Why is regex so slow? Skip Montanaro <skip@pobox.com> - 2013-06-18 12:01 -0500
  Re: Why is regex so slow? Roy Smith <roy@panix.com> - 2013-06-18 13:08 -0400
  Re: Why is regex so slow? Chris Angelico <rosuav@gmail.com> - 2013-06-19 03:20 +1000
    Re: Why is regex so slow? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2013-06-18 20:10 +0200
      Re: Why is regex so slow? Roy Smith <roy@panix.com> - 2013-06-18 12:40 -0700
      Re: Why is regex so slow? André Malo <ndparker@gmail.com> - 2013-06-18 21:59 +0200
        Re: Why is regex so slow? André Malo <ndparker@gmail.com> - 2013-06-18 22:13 +0200
  Re: Why is regex so slow? MRAB <python@mrabarnett.plus.com> - 2013-06-18 18:31 +0100
  Re: Why is regex so slow? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-06-18 18:34 +0100
    Re: Why is regex so slow? roy@panix.com (Roy Smith) - 2013-06-18 15:21 -0400
      Re: Why is regex so slow? MRAB <python@mrabarnett.plus.com> - 2013-06-18 20:49 +0100
  Re: Why is regex so slow? Rick Johnson <rantingrickjohnson@gmail.com> - 2013-06-18 12:21 -0700
  Re: Why is regex so slow? Antoine Pitrou <solipsis@pitrou.net> - 2013-06-18 20:05 +0000
    Re: Why is regex so slow? Roy Smith <roy@panix.com> - 2013-06-18 13:23 -0700
      Re: Why is regex so slow? Duncan Booth <duncan.booth@invalid.invalid> - 2013-06-19 13:21 +0000
        Re: Why is regex so slow? Roy Smith <roy@panix.com> - 2013-06-19 12:55 -0700
    Re: Why is regex so slow? Grant Edwards <invalid@invalid.invalid> - 2013-06-18 20:30 +0000
      Re: Why is regex so slow? Terry Reedy <tjreedy@udel.edu> - 2013-06-18 17:29 -0400
      Re: Why is regex so slow? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2013-06-19 10:29 +0200
  Re: Why is regex so slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-19 01:51 +0000
    Re: Why is regex so slow? Dave Angel <davea@davea.name> - 2013-06-18 22:11 -0400
      Re: Why is regex so slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-06-19 03:16 +0000

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