#!/usr/bin/env perl

use 5.010;
use strict;
use warnings;
use autodie;

my $header = '';
my (@headers_found, %header_data);

open my $fasta_fh, '<', $ARGV[0];

while (<$fasta_fh>) {
    chomp;
    next if /^\s*($|#)/;
    
    if (/^>(.*)$/) {
        push @headers_found, ($header = $1);
    }
    else {
        die 'Sequence data found without a header!' unless $header; 
        
        for (split '', "\U$_") {
            /(?<a>[DNEQ])|(?<b>[KRH])|(?<n>.)/;
            ++$header_data{$header}{(keys %+)[0]};
        }
    }
}

close $fasta_fh;

for (@headers_found) {
    say "Header: $_";
    say "\tAcidic:  $header_data{$_}{a}";
    say "\tBasic:   $header_data{$_}{b}";
    say "\tNeutral: $header_data{$_}{n}";
}

##</code><code>##

$ pm_fasta_amino_charge_calc.pl pm_mtmccs_data_modified.fasta
Header: DROTME_HH_Q02936 
        Acidic:  14
        Basic:   18
        Neutral: 67
Header: DROME_HH_Q02937 
        Acidic:  33
        Basic:   35
        Neutral: 136
Header: DROME_HH_Q02938 
        Acidic:  18
        Basic:   17
        Neutral: 69