Asp Forum - Deleting Text From a File

woodyee

11/28/2007 2:39:00 PM

Hi! I had to manually remove decimals and tildes from a text file. How
could I have done this via programming? I googled this but didn't
really find anything, just stuff on removing spaces. Basically, I'd
like to be able to search a file and remove certain items (ex - all
decimals and tildes). Thanks!

7 Answers

Alex Young

11/28/2007 2:44:00 PM

woodyee wrote:
> Hi! I had to manually remove decimals and tildes from a text file. How
> could I have done this via programming? I googled this but didn't
> really find anything, just stuff on removing spaces. Basically, I'd
> like to be able to search a file and remove certain items (ex - all
> decimals and tildes). Thanks!
>
Sounds like a job for regular expressions. Have you got a short before
and after example?

--
Alex

woodyee

11/28/2007 4:26:00 PM

On Nov 28, 9:44 am, Alex Young <a...@blackkettle.org> wrote:
> woodyee wrote:
> > Hi! I had to manually remove decimals and tildes from a text file. How
> > could I have done this via programming? I googled this but didn't
> > really find anything, just stuff on removing spaces. Basically, I'd
> > like to be able to search a file and remove certain items (ex - all
> > decimals and tildes). Thanks!
>
> Sounds like a job for regular expressions. Have you got a short before
> and after example?
>
> --
> Alex

Sure. See below. Basically, the entire document was like this. To me,
Reg Exp's were the key but they're a weakness of mine so I was
lost. :-)

Original
---------
89.00~~~~
6330.00~15~CAT1~0005~1.00

Modified
----------
89
6330 15 CAT1 0005 1

Alex Young

11/28/2007 4:39:00 PM

woodyee wrote:
> On Nov 28, 9:44 am, Alex Young <a...@blackkettle.org> wrote:
>> woodyee wrote:
>>> Hi! I had to manually remove decimals and tildes from a text file. How
>>> could I have done this via programming? I googled this but didn't
>>> really find anything, just stuff on removing spaces. Basically, I'd
>>> like to be able to search a file and remove certain items (ex - all
>>> decimals and tildes). Thanks!
>> Sounds like a job for regular expressions. Have you got a short before
>> and after example?
>>
>> --
>> Alex
>
> Sure. See below. Basically, the entire document was like this. To me,
> Reg Exp's were the key but they're a weakness of mine so I was
> lost. :-)
>
>
> Original
> ---------
> 89.00~~~~
> 6330.00~15~CAT1~0005~1.00
>
> Modified
> ----------
> 89
> 6330 15 CAT1 0005 1
>

irb(main):001:0> file = "89.00~~~~
irb(main):002:0" 6330.00~15~CAT1~0005~1.00
irb(main):003:0"
irb(main):004:0" "
=> "89.00~~~~\n6330.00~15~CAT1~0005~1.00\n\n"
irb(main):005:0> file.gsub(/\.\d+/, '').tr('~', ' ')
=> "89 \n6330 15 CAT1 0005 1\n\n"
irb(main):006:0> puts _
89
6330 15 CAT1 0005 1

I think that should do it :-) I don't think it's feasible to do it all
in a single pass, which is why I've gone for separate gsub and tr phases.

--
Alex

MonkeeSage

11/28/2007 5:07:00 PM

On Nov 28, 8:38 am, woodyee <wood_ye...@hotmail.com> wrote:
> Hi! I had to manually remove decimals and tildes from a text file. How
> could I have done this via programming? I googled this but didn't
> really find anything, just stuff on removing spaces. Basically, I'd
> like to be able to search a file and remove certain items (ex - all
> decimals and tildes). Thanks!

How about...

"he~~ll.o".tr('~.', '') # => "hello"

String#tr translates a group of characters into another group, such
that for every character in a given position in group one, it is
replaced by the character in the same position in group two, or if
group two is shorter, it uses the last character in group two. In this
case, group two is empty, so everything in group one is replaced with
empty strings (i.e., deleted).

HTH,
Jordan

yermej

11/28/2007 7:00:00 PM

On Nov 28, 8:38 am, woodyee <wood_ye...@hotmail.com> wrote:
> Hi! I had to manually remove decimals and tildes from a text file. How
> could I have done this via programming? I googled this but didn't
> really find anything, just stuff on removing spaces. Basically, I'd
> like to be able to search a file and remove certain items (ex - all
> decimals and tildes). Thanks!

This will remove all decimals and tildes and create a backup of the
original file with the extension .bak (from the command line):

ruby -i.bak -n -e 'print $_.gsub(/[\.~]/, "")' input_file.txt

Jeremy

woodyee

11/28/2007 9:51:00 PM

On Nov 28, 2:00 pm, yermej <yer...@gmail.com> wrote:
> On Nov 28, 8:38 am, woodyee <wood_ye...@hotmail.com> wrote:
>
> > Hi! I had to manually remove decimals and tildes from a text file. How
> > could I have done this via programming? I googled this but didn't
> > really find anything, just stuff on removing spaces. Basically, I'd
> > like to be able to search a file and remove certain items (ex - all
> > decimals and tildes). Thanks!
>
> This will remove all decimals and tildes and create a backup of the
> original file with the extension .bak (from the command line):
>
> ruby -i.bak -n -e 'print $_.gsub(/[\.~]/, "")' input_file.txt
>
> Jeremy

WOW! It worked and it was so cool!! Thanks! One thing I did - I
modified it to delete the .00's:

ruby -i.bak -n -e 'print $_.gsub(/[\.00~]/, " ")' input_file.txt

This worked but it deleted the zero in front of the decimal. How can I
avoid this? Thanks! :-)

yermej

11/28/2007 10:25:00 PM

On Nov 28, 3:50 pm, woodyee <wood_ye...@hotmail.com> wrote:
> On Nov 28, 2:00 pm, yermej <yer...@gmail.com> wrote:
>
> > On Nov 28, 8:38 am, woodyee <wood_ye...@hotmail.com> wrote:
>
> > > Hi! I had to manually remove decimals and tildes from a text file. How
> > > could I have done this via programming? I googled this but didn't
> > > really find anything, just stuff on removing spaces. Basically, I'd
> > > like to be able to search a file and remove certain items (ex - all
> > > decimals and tildes). Thanks!
>
> > This will remove all decimals and tildes and create a backup of the
> > original file with the extension .bak (from the command line):
>
> > ruby -i.bak -n -e 'print $_.gsub(/[\.~]/, "")' input_file.txt
>
> > Jeremy
>
> WOW! It worked and it was so cool!! Thanks! One thing I did - I
> modified it to delete the .00's:
>
> ruby -i.bak -n -e 'print $_.gsub(/[\.00~]/, " ")' input_file.txt
>
> This worked but it deleted the zero in front of the decimal. How can I
> avoid this? Thanks! :-)

Typically, when you characters in [], it means to match any character
in that group. So, [\.00~] is the same as [\.0~] is the same as [0\.~]
etc. so you removed all occurrences of 0, ., and ~ no matter what
surrounded them.

If you want to delete just .00 and ~, try:

/\.00|~/

as the first argument to gsub. That means match .00 or ~ and nothing
else.

This is probably a decent site if you want to learn more about regular
expressions:
http://www.regular-expressions.info/tut...

Jeremy

comp.lang.ruby

Deleting Text From a File

woodyee

Alex Young

woodyee

Alex Young

MonkeeSage

yermej

woodyee

yermej

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