Aaron Toponce : Perl Versus Ruby on CSV

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 <code> 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(<in>) # </in> (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

Perl Versus Ruby on CSV

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