How can I sort this data on the first field

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: How can I sort this data on the first field by gaal (Parson) on Apr 25, 2005 at 06:57 UTC
`my @sorted = map { $_->[1] } # pick interesting data sort { $a->[0] <=> $b->[0] } # sort numerically on first field map { [ split /\\|/, $_, 2 ] } # extract sortable field: $_->[0] i +s sortable, # $_->[1] i +s data <DATA>;` [download] This is a simple variant of the Schwartzian Transform. Read it upwards. In the original transform, the original data is kept around as one of the elements of @$_. Here I was assuming you didn't need to display the sort number — but if you did, then you need to do something slightliy different than a split.	[reply] [d/l]
Re: How can I sort this data on the first field by ColtsFoot (Chaplain) on Apr 25, 2005 at 06:55 UTC
Take a look at the Sort::Fields package Sort::Fields provides a general purpose technique for efficiently sorting lists of lines that contain data separated into fields.	[reply]
Re: How can I sort this data on the first field by prasadbabu (Prior) on Apr 25, 2005 at 06:57 UTC
If i understood your question correctly, is this you want, `while(<DATA>) { chomp; @cpy=(); @cpy = split(/\\|/); $cpy{$cpy[0]} = [@cpy]; } print "$_->[0]\t$_->[1]\n" for sort {$a->[0] <=> $b->[0]} values %cpy;` [download] `output: 30 microsoft 35 mozilla 40 opera 70 aol 76 netscape` [download] updated: Prasad	[reply] [d/l] [select]
Re^2: How can I sort this data on the first field by Anonymous Monk on Apr 25, 2005 at 07:08 UTC
Thank you very much Prasad!	[reply]
Re: How can I sort this data on the first field by Roy Johnson (Monsignor) on Apr 25, 2005 at 12:16 UTC
Since your numbers are the initial field, and are terminated by non-numbers, you can just treat the whole string as a number and Perl will Do The Right Thing: `print sort {$a <=> $b} <DATA>; __DATA__ 30\|microsoft 70\|aol 76\|netscape 5\|trouble? 35\|mozilla 40\|opera` [download] No need for splitting or Schwartzian Transforms. Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re^2: How can I sort this data on the first field by NateTut (Deacon) on Apr 25, 2005 at 20:30 UTC
Roy Johnson's solution works, but it is not warning free. The original problem seems to me to scream out for the use of a hash. Here is how I would have approached the problem: `use strict; use warnings; print "Content-type: text/html\n\n"; my %someData; while(<DATA>) { chomp(); (my $key, my $value) = split(/\\|/, $_, 2); $someData{$key} = $value; } foreach (sort { $a <=> $b } keys %someData) { print "$_\{$someData{$_}\}\n"; } __DATA__ 30\|microsoft 70\|aol 76\|netscape 5\|trouble? 35\|mozilla 40\|opera 100\|FireFox` [download]	[reply] [d/l]
Re^3: How can I sort this data on the first field by Chady (Priest) on Apr 26, 2005 at 06:19 UTC
It's not a hash that you want... it's probably an array of arrays. What if there were duplicate keys? your hash will eat them up and you'll end up with only the last entry. compare: `print "With Hash:\n\n"; $save = tell DATA; while(<DATA>) { my ($k, $v) = split '\\|'; $hash{$k} = $v; } print "$_\|$hash{$_}" for sort { $a <=> $b } keys %hash; seek DATA, $save, 0; print "\n\nWith array:\n\n"; while(<DATA>) { my ($k, $v) = split '\\|'; push @arr, [$k, $v]; } print "$_->[0]\|$_->[1]" for sort { $a->[0] <=> $b->[0] } @arr; __DATA__ 30\|microsoft 70\|aol 76\|netscape 5\|trouble? 35\|mozilla 30\|die microsoft 40\|opera 100\|FireFox 5\|no more trouble` [download] He who asks will be a fool for five minutes, but he who doesn't ask will remain a fool for life. Chady \| http://chady.net/ Are you a Linux user in Lebanon? join the Lebanese GNU/Linux User Group.	[reply] [d/l]
Re: How can I sort this data on the first field by tlm (Prior) on Apr 25, 2005 at 06:59 UTC
`print "<table>\n"; print for map sprintf( "<tr><td>%d</td><td>%s</td></tr>\n", @$_ ), sort { $a->[ 0 ] <=> $b->[ 0 ] } map { chomp; [ split /\\|/ ] } <DATA>; print "</table>\n";` [download] the lowliest monk	[reply] [d/l]
Re: How can I sort this data on the first field by salva (Canon) on Apr 25, 2005 at 08:35 UTC
use Sort::Key; my @sorted = ikeysort { /^(\d)/; $1 } @data; or `my @sorted = ikeysort { no warnings; int $_ } @data;` [download] or even `my @sorted = sort { no warnings; $a <=> $b } @data;` [download] update:* oops, "no warnings" can not be used inside the comparison expression, so... `my @sorted; { no warnings; @sorted = sort { $a <=> $b } @data; }` [download] ... has to be used instead	[reply] [d/l] [select]
Re: How can I sort this data on the first field by TedPride (Priest) on Apr 25, 2005 at 07:29 UTC
I know there are several working examples above, but they all seem to be longer, more obfuscated, or don't include the creation code for the array. Props to the guy with the table code, though :) Here's mine. `use strict; use warnings; my ($c, @data); while (<DATA>) { chomp; $data[$c++] = [split /\\|/]; } print join('\|', @$_) . "\n" for (sort {@$a[0] <=> @$b[0]} @data); __DATA__ 30\|microsoft 70\|aol 76\|netscape 35\|mozilla 40\|opera` [download]	[reply] [d/l]
Re^2: How can I sort this data on the first field by Chady (Priest) on Apr 25, 2005 at 09:48 UTC
The funny thing is that your version can be extremely shortened to this: `print sort <DATA>; __DATA__ 30\|microsoft 70\|aol 76\|netscape 35\|mozilla 40\|opera` [download] He who asks will be a fool for five minutes, but he who doesn't ask will remain a fool for life. Chady \| http://chady.net/ Are you a Linux user in Lebanon? join the Lebanese Linux User Group.	[reply] [d/l]
Re^3: How can I sort this data on the first field by jhourcle (Prior) on Apr 25, 2005 at 13:28 UTC
The example can, but as soon as you have numbers that are a different order of magnitude, it will fail: `print sort <DATA>; __DATA__ 9\|microsoft 70\|aol 108\|netscape 35\|mozilla 40\|opera` [download] Based on the similarity of this example, with that in Need help with searching flatfile and updating it., I can only assume that the numbers aren't going to remain static.	[reply] [d/l]
Re^4: How can I sort this data on the first field by Chady (Priest) on Apr 25, 2005 at 17:29 UTC
Re: How can I sort this data on the first field by sh1tn (Priest) on Apr 25, 2005 at 09:31 UTC
One short sorting step: `my %sort = map{ /^(\d+)\\|(\w+)/ and $1, $2 } <DATA>; print "$_ - $sort{$_} \n" for sort keys %sort;` [download]	[reply] [d/l]
Re: How can I sort this data on the first field by TedPride (Priest) on Apr 25, 2005 at 10:22 UTC
Chady: Yes, but that only works if the number remains exactly two characters long. I highly doubt that is the case.	[reply]
Re^2: How can I sort this data on the first field by chas (Priest) on Apr 25, 2005 at 12:33 UTC
What if you use `print sort {$a<=>$b} <DATA>;`? chas (Update: Posted after reading an unrefreshed page and didn't realize Roy Johnson had already suggested the same thing.)	[reply] [d/l]