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Re: Regular expression [message #53863 is a reply to message #36958]

Fri, 04 May 2007 09:36

lasse
Messages: 48
Registered: February 2007

Member

On 4 May, 16:56, Allan Whiteford
<allan.rem...@phys.remove.strath.ac.remove.uk> wrote:
> Lasse,
>
> Either:
>
> regex='[a-zA-Z0-9]+\[[0-9]+\]'
>
> or:
>
> regex='[a-zA-Z0-9]{2}\[[0-9]{2}\]'
>
> depending on whether your 'bb' and '23' need to be exactly two
> characters long or not.
>
> Note also you may want to check whether you're matching a substring
> inside your search string or the complete string. I'm not sure what you
> want to do.
>
> Thanks,
>
> Allan
>
> Lasse Clausen wrote:
>> On 4 May, 16:21, FÖLDY Lajos <f...@rmki.kfki.hu> wrote:
>
>>> On Fri, 4 May 2007, Lasse Clausen wrote:
>
>>>> Hi there,
>
>>>> why does
>
>>>> print, stregex('[', '[\[]')
>
>>>> work, i.e. produce 0, whereas
>
>>> You are searching for \ or [ ==> found.
>
>>>> print, stregex(']', '[\]]')
>
>>>> prints -1?
>
>>> You are searching for \ followed by ] ==> not found.
>
>>>> print, stregex(']', '\]')
>
>>>> works (i.e. prints 0).
>
>>> You are searching for ] ==> found.
>
>>> \ loses its 'escape char' meaning in a bracket expression, and becomes an
>>> ordinary character.
>
>>> regards,
>>> lajos
>
>> mhmm, don't understand. Ok, here we go: I have a string like this
>
>> bb[23]
>
>> where bb can be any combination of alphanumerics and the number can be
>> anything. I am looking for the regular expression that will match the
>> whole thing. My first idea was (at the moment I am not bothered about
>> the order of the different parts):
>
>> regex = '[a-zA-Z0-9\[\]]+'
>
>> but alas!
>
>> print, stregex('bb[23]', regex)
>> 4
>
>> What?! And any combination of omitting or changing the \ character
>> will result in either IDL complainign about non-balanced brackets, a
>> match at position 4 or it won't match.
>
>> Help?
>
>> Cheers
>> Lasse

Thanks for the reply. I realized that I could do it the way you
(Allan) proposed, without including the brackets in the character
group, but I was being more academic and looking for a way to include
them in the character group. The following works

print, stregex('bb[23]', '[][0-9a-b]+', length=length) & print, length
0
6

however, order is, not surprisingly, essential:

print, stregex('bb[23]', '[[]0-9a-b]+', length=length) & print, length
-1
-1

Cheers
Lasse

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[Message index]

		regular expressions (parsing strings) By: setthivoine you on Wed, 12 November 2003 12:04
		Re: Regular expression By: Foldy Lajos on Fri, 04 May 2007 11:13
		Re: Regular expression By: James Kuyper on Fri, 04 May 2007 10:44
		Re: Regular expression By: lasse on Fri, 04 May 2007 09:36
		Re: Regular expression By: Allan Whiteford on Tue, 08 May 2007 05:10
		Re: Regular expression By: Foldy Lajos on Fri, 04 May 2007 09:04
		Re: Regular expression By: Allan Whiteford on Fri, 04 May 2007 08:56
		Re: Regular expression By: lasse on Fri, 04 May 2007 08:46
		Re: Regular expression By: Allan Whiteford on Fri, 04 May 2007 08:41
		Re: Regular expression By: Foldy Lajos on Fri, 04 May 2007 08:21

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