Re: Regex substitution trouble

Return-Path	<rosuav@gmail.com>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.004
X-Spam-Evidence	'H': 0.99; 'S': 0.00; 'python,': 0.02; 'string.': 0.05; 'string': 0.09; 'skip:$ 30': 0.09; 'yeah,': 0.09; 'cc:addr :python-list': 0.11; 'python': 0.11; 'suggest': 0.14; 'backslash': 0.16; 'backslash,': 0.16; 'expressions,': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'occurences': 0.16; 'ought': 0.16; 'problem!': 0.16; 'regex,': 0.16; 'substitute': 0.16; ':-)': 0.16; 'wrote:': 0.18; 'trying': 0.19; 'cc:addr:python.org': 0.22; 'string,': 0.24; 'cc:2**0': 0.24; 'sort': 0.25; 'header:In-Reply-To:1': 0.27; 'correct': 0.29; 'message-id:@mail.gmail.com': 0.30; "i'm": 0.30; 'that.': 0.31; 'anyone': 0.31; 'file': 0.32; 'regular': 0.32; 'another': 0.32; 'text': 0.33; 'could': 0.34; 'problem.': 0.35; 'something': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'really': 0.36; 'possible': 0.36; 'handle': 0.38; 'pm,': 0.38; 'that,': 0.38; 'anything': 0.39; 'itself': 0.39; 'sure': 0.39; 'such': 0.63; 'networking': 0.64; 'different': 0.65; 'here': 0.66; 'surrounding': 0.68; 'skip:r 30': 0.69; 'legal': 0.71; 'loose': 0.84; 'presumably': 0.84; 'to:none': 0.92
DKIM-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=y+fEyib7gWroidtgDDpykaFbPvkCw4qVzuPvz9poME4=; b=r0VLShMFAS2jLulOpFrSkbEQVGTJ23V78ndzh0GMsknpKIjvKV2vdPcl5hsJUiRy3+ nn0HYCIvtG6MPFFdVSkTbaqPqhI4f1gZwUJ67zlVveGOdRTKEfae2avvHV8g643Aj42A wdhcQ8E3AwHWRT1+E/qiZYSMEw+wvxkVYW09w2cat+v5xZaAZIt4R0Kuqe1p5syT7Xai YFKcLb8J6tU+NaLIdopAsGlmh/YSA5/MvCUfekEVusKUApiAlD5MaKfu7uc/lj0N55K6 TXaywaauRTcOBDNWOAywGrvIvzXrsubd/HU1d2ZCYZjVnDqubpCVWOiq51V4sZdB8WFp I9nA==
MIME-Version	1.0
X-Received	by 10.43.66.193 with SMTP id xr1mr3033395icb.59.1414495482542; Tue, 28 Oct 2014 04:24:42 -0700 (PDT)
In-Reply-To	<8c1c1b7f-d121-4f3d-adf9-8262ddd8f102@googlegroups.com>
References	<8c1c1b7f-d121-4f3d-adf9-8262ddd8f102@googlegroups.com>
Date	Tue, 28 Oct 2014 22:24:42 +1100
Subject	Re: Regex substitution trouble
From	Chris Angelico <rosuav@gmail.com>
Cc	"python-list@python.org" <python-list@python.org>
Content-Type	text/plain; charset=UTF-8
X-BeenThere	python-list@python.org
X-Mailman-Version	2.1.15
Precedence	list
List-Id	General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe	<https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.15258.1414495491.18130.python-list@python.org> (permalink)
Lines	22
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1414495491 news.xs4all.nl 2972 [2001:888:2000:d::a6]:32859
X-Complaints-To	abuse@xs4all.nl
Path	csiph.com!usenet.pasdenom.info!bete-des-vosges.org!feed.ac-versailles.fr!proxad.net!feeder1-2.proxad.net!news.tele.dk!news.tele.dk!small.news.tele.dk!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Xref	csiph.com comp.lang.python:79835

Show key headers only | View raw

On Tue, Oct 28, 2014 at 10:02 PM,  <massi_srb@msn.com> wrote:
> I'm not really sure if this is the right place to ask about regular expressions, but since I'm usin python I thought I could give a try :-)

Yeah, that sort of thing is perfectly welcome here. Same with
questions about networking in Python, or file I/O in Python, or
anything like that. Not a problem!

> Here is the problem, I'm trying to write a regex in order to substitute all the occurences in the form $"somechars" with another string. This is what I wrote:
>
> newstring = re.sub(ur"""(?u)(\$\"[\s\w]+\")""", subst, oldstring)
>
> This works pretty well, but it has a problem, I would need it also to handle the case in which the internal string contains the double quotes, but only if preceeded by a backslash, that is something like $"somechars_with\\"doublequotes".
> Can anyone help me to correct it?

But this is a problem. You can use look-ahead assertions and such to
allow the string \" inside your search string, but presumably the
backslash ought itself to be escapable, in order to make it possible
to have a loose backslash legal at the end of the string. I suggest
that, instead of a regex, you look for a different way of parsing.
What's the surrounding text like?

ChrisA

Thread

Regex substitution trouble massi_srb@msn.com - 2014-10-28 04:02 -0700
  Re: Regex substitution trouble Chris Angelico <rosuav@gmail.com> - 2014-10-28 22:24 +1100
    Re: Regex substitution trouble massi_srb@msn.com - 2014-10-28 05:28 -0700
      Re: Regex substitution trouble Chris Angelico <rosuav@gmail.com> - 2014-10-28 23:59 +1100
      Re: Regex substitution trouble MRAB <python@mrabarnett.plus.com> - 2014-10-28 17:52 +0000
  Re: Regex substitution trouble TP <wingusr@gmail.com> - 2014-10-28 06:25 -0700
  Re: Regex substitution trouble Tim <jtim.arnold@gmail.com> - 2014-10-28 09:38 -0700
  Re: Regex substitution trouble Cameron Simpson <cs@zip.com.au> - 2014-10-29 13:14 +1100
  Re: Regex substitution trouble Eugene <hexumg@gmail.com> - 2014-11-05 13:44 +0300

csiph-web