Perl Versus Ruby on CSV

Aaron — Sat, 30 Dec 2006 02:15:13 +0000

Ok. I had a little project at work, at which point, I turned to Perl to accomplish the task. The project was simple enough: take a comma-separated file, and look at a few fields to see what data is contained. Based on that data, create a “weight”, and assign the weight to the record at the end of the line.

The Perl code I used to accomplish the task is as follows (please take note, that Wordpress loves to parse tags, even if contained within tags. Wordpress also likes to lowercase the tag, so in Perl, file handles will be in lowercase):


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#!/usr/bin/perl -w



open(IN, "UNIVERSE.csv");

open(OUT, ">UNIVERSE_WEIGHTED.csv");



$counter = 0;



while() #  (for Wordpress)

{

    @fields = split(/,/,$_,183);

    $fields[182] =~ s/\n//;

    s/\n//;

    $counter++;

    $weight = 0;



    if ($counter == 1)

    {

        print OUT $_ . ",\"weight\"\n";

    }

    else

    {

        $vtr_ppp00 = $fields[154];

        $vtr_ppp04 = $fields[155];

        $vtr_pri01 = $fields[161];

        $vtr_pri03 = $fields[163];

        $vtr_pri05 = $fields[165];

        $vtr_pri99 = $fields[182];



        $weight +=.5 if ($vtr_ppp00 eq "\"R\"");

        $weight -= 1 if ($vtr_ppp04 eq "\"D\"");

        $weight -= 1 if ($vtr_pri01 eq "\"D\"");

        $weight -= 1 if ($vtr_pri03 eq "\"D\"");

        $weight -= 1 if ($vtr_pri05 eq "\"D\"");

        $weight -= 1 if ($vtr_pri99 eq "\"D\"");

        $weight += 1 if ($vtr_ppp04 eq "\"R\"");

        $weight += 1 if ($vtr_pri01 eq "\"R\"");

        $weight += 1 if ($vtr_pri03 eq "\"R\"");

        $weight += 1 if ($vtr_pri05 eq "\"R\"");

        $weight += 1 if ($vtr_pri99 eq "\"R\"");

    

        print OUT $_ . ",\"" . $weight . "\"\n";

    }

    

    print "Processed: " . $counter . "\r";

}



print "\n";



close(IN);

close(OUT);
Just for fun, a buddy of mine mentioned to code it in Ruby, and compare results.  Seeing as though I have never coded a Ruby script in my life, I was a bit worried.  However, it wasn’t too bad.  I just had to cure my itch to put a $ in front of all my variables.  Anyway, heres the Ruby code, following as closely as possible to the Perl code:
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#!/usr/bin/ruby



counter = 0



outfile = File.open("UNIVERSE_RUBY.csv","w")

IO.foreach("UNIVERSE.csv") do |line|

    counter += 1

    weight = 0

    

    if (counter == 1)

        outfile < < line.chop + ",\"weight\"\n"

    else    

        fields = line.chop.split(',')

        vtr_ppp00 = fields[154]

        vtr_ppp04 = fields[155]

        vtr_pri01 = fields[161]

        vtr_pri03 = fields[163]

        vtr_pri05 = fields[165]

        vtr_pri99 = fields[182]

        

        weight += 0.5 if (vtr_ppp00 == "\"R\"")

        weight -= 1   if (vtr_ppp04 == "\"D\"")

        weight -= 1   if (vtr_pri01 == "\"D\"")

        weight -= 1   if (vtr_pri03 == "\"D\"")

        weight -= 1   if (vtr_pri05 == "\"D\"")

        weight -= 1   if (vtr_pri99 == "\"D\"")

        weight += 1   if (vtr_ppp04 == "\"R\"")

        weight += 1   if (vtr_pri01 == "\"R\"")

        weight += 1   if (vtr_pri03 == "\"R\"")

        weight += 1   if (vtr_pri05 == "\"R\"")

        weight += 1   if (vtr_pri99 == "\"R\"")

        

        outfile < < line.chop + ",\"" + weight.to_s + "\"\n"

    end

    print "Processed: " + counter.to_s + "\r"

end



print "\n"
Ok.  As you can see, the code is fairly similar.  The algorithms the same.  Running the script takes a mere second or two, and the file comes out correct.  However, I was curious about execution speed, so I decided to pit one script against the other, time them, and see what happens.  Here are my results
aaron@hercules:~/Desktop$ time perl weight.pl
Processed: 5394

real    0m1.386s
user    0m1.304s
sys     0m0.048s
aaron@hercules:~/Desktop$ time ruby weight.rb
Processed: 5394

real    0m2.180s
user    0m1.992s
sys     0m0.124s

Am I reading this correctly?  Perl is almost 60% faster at execution with this code than Ruby?  I thought Ruby was supposed to have exceptional file handling.  Better than Perl, even.  However, I have also heard that the Ruby devs are more concerned about functionality than speed, which should be expected.  Still, that’s a serious speed factor.  If I was worried about speed here, Perl, in this case, would win out.

At any rate, this was a fun little exercise to stretch my scripting muscles, and to learn a bit of Ruby. I’m curious if I can make the scripts more efficient. If you know how, comment below, or contact me.

Aaron Toponce » » Ruby

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Perl Versus Ruby on CSV