Python script which uses fonttools to output a table grouping glyphs in a font by their advance width.

glyphs_by_width.py

import argparse
import collections
from fontTools.ttLib import TTFont

__author__="Cody 'codeman38' Boisclair"

def main():
    parser = argparse.ArgumentParser(
        description="Group glyphs in a font by their advance width.")
    parser.add_argument('font', help='font file to parse')
    args = parser.parse_args()

    font = TTFont(args.font)
    width_dict = collections.defaultdict(list)
    metrics = font['hmtx'].metrics
    for name, metric in metrics.items():
        width = metric[0]
        width_dict[width].append(name)
    sorted_widths = width_dict.items()
    sorted_widths.sort(key=lambda x: (-len(x[1]), x[0]))
    print('Width\tCount\tGlyphs')
    for width, glyphs in sorted_widths:
        print('{0}\t{1}\t{2}'.format(
            width, len(glyphs), ' '.join(sorted(glyphs))))
    print('TOTAL\t{0}'.format(len(metrics)))

if __name__=='__main__':
    main()