fontforge script to generate subsets of fonts

genwebfonts.py

#!/usr/bin/env fontforge -lang=py -script
# -*- coding: utf-8 -*-

import fontforge
import sys
import os

def _select_codepoint(codepoint, selection, more=True):
    more_str = 'more' if more else 'less'
    if isinstance(codepoint, tuple) and len(codepoint) == 2:
        first, last = codepoint
        if isinstance(first, int) and isinstance(last, int):
            selection.select((more_str, 'ranges', 'unicode'), first, last)
        elif isinstance(first, unicode) and isinstance(last, unicode):
            selection.select((more_str, 'ranges', 'unicode'), ord(first), ord(last))
        else:
            message = 'invalid codepoint type: ' + str(codepoint)
            raise Exception(message)
    elif isinstance(codepoint, int):
        selection.select((more_str, 'unicode'), codepoint)
    elif isinstance(codepoint, unicode):
        for c in codepoint:
            selection.select((more_str, 'unicode'), ord(c))
    else:
        message = 'invalid codepoint type: ' + str(codepoint)
        raise Exception(message)

def _clear_unneeded_glyphs(font, codepoints):
    font.selection.all()
    for codepoint in codepoints:
        _select_codepoint(codepoint, font.selection, more=False)
    font.clear()

def generate_webfonts(input, outdir, codepoints):
    if not os.path.exists(outdir):
        os.mkdir(outdir)
    if not os.path.isdir(outdir):
        message = 'last argument is not directory: ' + outdir
        raise Exception(message)
    font = fontforge.open(input)
    _clear_unneeded_glyphs(font, codepoints)
    filename = os.path.split(input)[-1]
    basename, ext = os.path.splitext(filename)
    for newext in [ext, '.woff', '.eot']:
        output = os.path.join(outdir, basename + newext)
        font.generate(output)
    font.close()

if __name__ == '__main__':
    codepoints = [(0x0000, 0x03FF), (0x2200, 0x22FF)]
    if len(sys.argv) > 2:
        for input in sys.argv[1:-1]:
            generate_webfonts(input, sys.argv[-1], codepoints)
    else:
        print('usage: ' + sys.argv[0] + ' inputs... outdir')
        exit(1)

Wow. Just what I was looking for.