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Re: Using Cases or Position to Find Strings in a List of Strings

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  • Subject: [mg119531] Re: Using Cases or Position to Find Strings in a List of Strings
  • From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
  • Date: Wed, 8 Jun 2011 07:13:31 -0400 (EDT)

Hi Gregory,

no, you can just *use* StringCases. To find all files here that end
with .blend you would do:

files = {"~/.blender/9009.blend", "~/.blender/9211.blend", 
  "~/.blender/.bfont.ttf", "~/.blender/.Blanguages", 
  "~/.blender/bpydata", "~/.blender/Bpymenus", "~/.blender/plugins", 
  "~/.blender/quit.blend", "~/.blender/REVISION", 
  "~/.blender/scripts", "~/.blender/VERSION"}

Flatten@StringCases[files, ___ ~~ ".blend" ~~ EndOfString]

and you get

{"~/.blender/9009.blend", 
"~/.blender/9211.blend", 
"~/.blender/quit.blend"}

But maybe I missunderstood your problem. I wouldn't use of course
StringPosition because if you only want the strings and not the
positions that it is anyway the wrong function.

Cheers
Patrick


On Tue, 2011-06-07 at 13:10 -0400, Gregory Lypny wrote:
> Hi Patrick,
> 
> Yes, I suppose I could map StringCases across the list of strings and then collect all of the results that are not null, but I was hoping it could be done directly with Cases.
> 
> Thanks,
> 
> Gregory
> 
> 
> 
> 
> On Tue, Jun 7, 2011, at 6:51 AM, Patrick Scheibe wrote:
> 
> > Hi,
> > 
> > what about using StringCases and StringPosition?
> > 
> > Cheers
> > Patrick
> > 
> > On Tue, 2011-06-07 at 06:48 -0400, Gregory Lypny wrote:
> >> Hello everyone,
> >> 
> >> I have a list of strings called myListOfFilePaths and I want to find 
> >> which one of those strings ends in ".DS_Store" (a hidden file created by 
> >> the Mac OS).  I can pick it off using Select as
> >> 
> >> 	Select[myListOfFilePaths, StringMatchQ[#, ___ ~~ ".DS_Store" ~~ 
> >> EndOfString] &]
> >> 
> >> but I can't do it using Cases or Position
> >> 
> >> 	Cases[myListOfFilePaths, ___ ~~ ".DS_Store" ~~ EndOfString]
> >> 
> >> 	Position[myListOfFilePaths, ___ ~~ ".DS_Store" ~~ EndOfString]
> >> 
> >> despite the fact that Head[___ ~~ ".DS_Store" ~~ EndOfString] is StringExpression.  What am I doing wrong?
> >> 
> >> 	Regards,
> >> 
> >> 	Gregory
> >> 
> > 
> > 
> 




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