From: "David A. Black" <dblack@...>
Date: 2009-06-24T02:24:46+09:00
Subject: Re: formatting a listing

Hi --

On Wed, 24 Jun 2009, George George wrote:

> David A. Black wrote:
>> On Tue, 23 Jun 2009, George George wrote:
>>
>>> whitespace
>>> -6.3
>>> 7
>>>
>>> Produce an output such that:
>>> 1,-3.05,-6.3
>>
>> That's a spurious - before the 3, right?
>>
>>> 2,4,7
>>> 3,5
>>>
>>> or
>>> 1,-3.05,-6.3
>>> 2,4,7
>>> 3,5,0
>>
>> The example that I couldn't quite figure out was the one with input
>> like:
>>
>>    1 2,3 4
>>
>> or something like that. Anyway, a simple version (which may not handle
>> that case) is:
>>
>> $/ = "\n\n"  # if the input is definitely \n\n delimited
>>
>> cols = File.open("input.csv") do |fh|
>>    max = 0
>>    fh.map do |s|
>>      row = s.scan(/\S+/)
>>      max = [max, row.size].max
>>      row << "0" until row.size == max
>>      row
>>    end
>> end
>>
>>
>> David
>
> Hi David!
> Thanks for the reply but the output given by the above code again
> only produces a single column instead of multiple columns.  instead of
> given
> 1
> 2
> 3
> white space
> 3.05
> 4
> 5
> whitespace
> -6.3
> 7
>
> Produce an output such that:
> 1,-3.05,-6.3
> 2,4,7
> 3,5

Here's my input and output, along with the program:

$ cat george.rb
$/ = "\n\n"

cols = File.open("input.csv") do |fh|
   max = 0
   fh.map do |s|
     row = s.scan(/\S+/)
     max = [max, row.size].max
     row << "0" until row.size == max
     row
   end
end

rows = cols.transpose.map {|row| row.join(",") }

puts rows
$ cat input.csv
1
2
3

3.05
4
5

-6.3
7
$ ruby george.rb 
1,3.05,-6.3
2,4,7
3,5,0

The columns look OK. Note that the $/="\n\n" thing only works if your
input is separated by exactly that sequence. That might be the problem
you're having.


David

-- 
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