From: Peter Szinek <peter@...>
Date: 2007-11-09T03:04:13+09:00
Subject: Re: problem with zipfile.read -> array  (line by line)

Hi Christian,

> have anybody a hint how i could extract information  only for the
> first column in a zipped csv.
> The hole csv-file is in the array instead line by line as i'm
> expected, so i get only the first
> character.
> 
> #match_f.csv are 3-column and many millions row file.
> Zip::ZipFile.open("f:/base_data/match_df.zip",Zip::ZipFile::CREATE)
> {  |zipfile|
>  array=zipfile.read("match_df.csv" ).split("\t")
> puts array[0]
>    }

You can also use a csv library (e.g. fasterCSV 
http://fastercsv.rubyforge.org/, or the standard Ruby one).

If you want to process the file line by line, you should split it on 
"\n", then process each line. Code-snippet:

zipfile.read("match_df.csv" ).split.each do |row|
   puts row.split(",")[0]
end

In the second split, you should use the delimiter used in the csv file 
(\t for instance).


Cheers,
Peter
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