# Text parser / reformatting

**URL:** <https://www.ruby-forum.com/t/text-parser-reformatting/108902>\
**Category:** Ruby\
**Created:** [July 9, 2007, 9:42am UTC](https://www.ruby-forum.com/t/text-parser-reformatting/108902 "2007-07-09T09:42:42Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![lasastard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/58956e/32.png) [@lasastard](https://www.ruby-forum.com/u/lasastard)\
**Post date:** [July 9, 2007, 9:42am UTC](https://www.ruby-forum.com/t/text-parser-reformatting/108902/1 "2007-07-09T09:42:42Z")

</div>

Hi everyone,

I expect this is a rather trivial problem, but I just started using ruby  
and am a bit stuck right now.  
Here is what I want to do:

I have a text file, that contains information in the following format:

KOG0003  
At2g36170  
At3g52590  
CE15495  
7295730  
KOG0004  
Hs20476120  
YIL148w  
YKR094c  
SPAC11G7.04

Now, this has to go into a relational database. But right now this is  
not really a table. The desired output would look something like this:

KOG0003 At2g36170  
KOG0003 At3g52590  
KOG0003 CE15495  
KOG0003 7295730  
KOG0004 Hs20476120  
KOG0004 YIL148w  
KOG0004 YKR094c

Well, you get the picture. What I tried to do is to read the text file,  
than look for lines that start with a blank and replace that blank with  
the first word of the previous line, given that this line does in fact  
starts with a word (could also be selected by using KOG[0-9]\*). I  
thought of storing the KOG[0-9] in a variable, but overall I cant make  
it work and have no real idea how to solve this. Any help would be  
greatly appreciated. Guess for an experienced user this is a three-liner  
.\_.

Cheers,

Marc

---

<div class="post-metadata">

**Author:** ![lasastard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/58956e/32.png) [@lasastard](https://www.ruby-forum.com/u/lasastard)\
**Post date:** [July 9, 2007, 10:04am UTC](https://www.ruby-forum.com/t/text-parser-reformatting/108902/2 "2007-07-09T10:04:29Z")

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2007/7/9, Marc H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> ```
> At3g52590
> 
> ```
> 
> the first word of the previous line, given that this line does in fact  
> starts with a word (could also be selected by using KOG[0-9]\*). I  
> thought of storing the KOG[0-9] in a variable, but overall I cant make  
> it work and have no real idea how to solve this. Any help would be  
> greatly appreciated. Guess for an experienced user this is a three-liner

Hm… Maybe something like this:

key = nil  
ARGF.each do |line|  
line.chomp!  
case line  
when /^(\S+)/  
key = line.strip  
when /^\s+(\S+)/  
print key, " ", $1, “\n” if key  
else  
# ignore  
end  
end

Kind regards

robert

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<div class="post-metadata">

**Author:** ![lasastard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/58956e/32.png) [@lasastard](https://www.ruby-forum.com/u/lasastard)\
**Post date:** [July 9, 2007, 10:11am UTC](https://www.ruby-forum.com/t/text-parser-reformatting/108902/3 "2007-07-09T10:11:06Z")

</div>

Thanks you two, worked like a charm!

Cheers,

Marc

---

<div class="post-metadata">

**Author:** ![lasastard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/58956e/32.png) [@lasastard](https://www.ruby-forum.com/u/lasastard)\
**Post date:** [July 9, 2007, 10:05am UTC](https://www.ruby-forum.com/t/text-parser-reformatting/108902/4 "2007-07-09T10:05:30Z")

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On 9 Jul 2007, at 16:42, Marc H. wrote:

> ```
> At2g36170
> 
> ```
> 
> not really a table. The desired output would look something like this:  
> file,  
> Cheers,
> 
> Marc
> 
> –  
> Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/).

Not a very fancy solution, but it seems to work for the data you  
posted. Also uses the pattern you suggested, storing the KOG\*  
identifier in a variable (field1):

[alexg@powerbook]/Users/alexg/Desktop(7): cat test.rb  
field1 = nil  
IO.foreach(ARGV[0]) do |l|  
if l.match(/^(\S+)/)  
field1 = $1  
else  
puts “#{field1} #{l.strip}”  
end  
end  
[alexg@powerbook]/Users/alexg/Desktop(8): cat data.dat  
KOG0003  
At2g36170  
At3g52590  
CE15495  
7295730  
KOG0004  
Hs20476120  
YIL148w  
YKR094c  
SPAC11G7.04  
[alexg@powerbook]/Users/alexg/Desktop(9): ruby test.rb data.dat  
KOG0003 At2g36170  
KOG0003 At3g52590  
KOG0003 CE15495  
KOG0003 7295730  
KOG0004 Hs20476120  
KOG0004 YIL148w  
KOG0004 YKR094c  
KOG0004 SPAC11G7.04

Alex G.

Bioinformatics Center  
Kyoto University