use strict;
use warnings;

my %res;
while (<DATA>) {
    my ( $name, $weight ) = split /\s+/;
    push @{ $res{$name} }, $weight;
}
for ( sort keys %res ) {
    print "$_ ", join( ",", @{ $res{$_} } ), "\n";
}

__DATA__
jim  14
john 23
ernest 38
matilda 43
jim 34
ernest 27
john 44
matilda 22
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