Sort glyphs in UFO by increasing Unicode codepoint

optimize_glyph_order.py

"""Sort glyphs in UFO by increasing Unicode codepoint to try shrinking the
size of the cmap table.
"""
import sys
from defcon import Font

try:
    font = Font(sys.argv[1])
except IndexError:
    sys.exit("usage: optimize_glyph_order.py FONT.ufo")

# sort glyphs by increasing unicode codepoint; put unencoded glyphs last
new_order = sorted(
    font.glyphOrder,
    key=lambda gn: font.unicodeData.unicodeForGlyphName(gn) or sys.maxsize,
)
# ensure .notdef is first glyph, if present
try:
    new_order.insert(0, new_order.pop(new_order.index(".notdef")))
except ValueError:
    pass

font.glyphOrder = new_order
font.save()