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Re: Selecting successive lines

by kcott (Archbishop)
on Sep 17, 2013 at 04:05 UTC ( [id://1054382]=note: print w/replies, xml ) Need Help??


in reply to Selecting successive lines

G'day zee3b,

You can read that data in paragraph mode (see perlvar for details): basically, this allows you to read each group of three lines as a single record. When you do this, you can grab the name, from line 1, and the score, from the end of line 3, in a single operaton.

#!/usr/bin/env perl -l use strict; use warnings; my %score; { local $/ = ""; while (<DATA>) { /\A(\w+).*?(\d+)\D*\z/ms; ++$score{$1}{count}; $score{$1}{total} += $2; } } for (sort keys %score) { print $_, ' Average ', $score{$_}{total} / $score{$_}{count}; } __DATA__ Jack Student ID - 12445 Math Score - 45 Jill Student ID - 234254 Math Score - 90 Jack Student ID -12445 Math Score2 - 33 Jill Student ID - 234254 Math Score2 - 10

Output:

$ pm_file_parse_avg.pl Jack Average 39 Jill Average 50

For your real application, you'll probably also want either int for whole number averages, or sprintf to format floating point results.

-- Ken

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Re^2: Selecting successive lines
by marinersk (Priest) on Sep 17, 2013 at 10:02 UTC

    You can read that data in paragraph mode (see perlvar for details)

    OMG I have been doing this the hard way (with manual parse phase state and similar techniques) for over a decade.

    :: facepalm ::

    Off to read now. And let the blush drain from my face.

    Thanks for the reference!

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