but how do I print the value from the 'good' key in the hash of hashes?
Loop through the keys of the primary hash, and print out the 'good' values if 'good' keys exist: 
use strict;
use warnings;
use Data::Dumper;

my %clone_hash;

while (<DATA>) {
    my ($key, $value) = split;
    my $grade = ($value =~ /^pass[1-3]$/) ? 'good' : 'bad';
    $clone_hash{$key}{$grade}++;
}
#print Dumper(\%clone_hash);

# Print out the 'good' keys
for (keys %clone_hash) {
    print "$_ => $clone_hash{$_}{good}\n" if exists $clone_hash{$_}{go
+od};
}

__DATA__
Eif2b2    fail
Eif2b2    pass5
Eif2b2    fail
Eif2b2    pass2
Eif2b2    fail
Eif2b2    pass4
Eif2b2    fail
49334    fail
49334    fail
49334    pass1
49334    fail
49334    pass4
Oxct1    pass4
Oxct1    fail
Oxct1    pass4
Oxct1    fail

[download]

which prints: 

Eif2b2 => 1
49334 => 1

[download]

In reply to Re^3: processing key value pairs of a hash by toolic
in thread processing key value pairs of a hash by lomSpace

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