[Chicago-talk] Performance issue
tiger peng
tigerpeng2001 at yahoo.com
Wed Apr 20 09:49:03 PDT 2011
why split and join? try replace '","' with '|' directly.
________________________________
From: Jay Strauss <me at heyjay.com>
To: Chicago.pm chatter <chicago-talk at pm.org>
Sent: Wed, April 20, 2011 11:37:47 AM
Subject: [Chicago-talk] Performance issue
Hi all,
I have a csv file, with quoted strings (i.e. "field1","field2",...). The file
is 3.5M records. I'm running strawberry perl on win7 (not that I think that's
the issue). What I need to do is convert any embedded "|" to "-", convert the
field delimiter ' "," ' to "|". I know there are cpan mods for parsing csv but
my situation is pretty straight forward. I'm doing:
use strict;
while(<>) {
$_ = substr $_, 1, -2; #Remove first and last ", and remove
#the \n at the same time
#
s/\|/-/g; # Change embedded "|" into "-"
my @words = split(/\",\"/,$_,-1);# split on the remaining ","
print join("|", @words),"\n";
}
But it's take what seems like a long time to run (like 15 mins). I'd think this
would be an ideal use for Perl, and could rip through the file lickedy split.
I'm I doing something costly in the script above that is making it run so slow?
Thanks
Jay
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