Go through all selected glyphs, and change whether they are set to export or non-export, based on the opposite of the state of the first glyph.

toggle_nonExport.py

# menuTitle: Skip Export - Mass Toggle Selected 

'''
Go through all selected glyphs, and change whether they are set to export or non-export, based on the opposite of the state of the first glyph.

2021.10.28
'''

f = CurrentFont()

# check to see if the public.skipExportGlyphs key is in the lib. if not, make it
try:
    # stephen’s duplicate-clean-up step, but sandwiched in here
    f.lib['public.skipExportGlyphs'] = list(set(f.lib['public.skipExportGlyphs']))
except:
    f.lib['public.skipExportGlyphs'] = []

# starting empty lists to print out later when filled
non_exp = []
exp = []

# check first glyph of selection, and plan to set everything to the opposite state of that
if f.selectedGlyphNames[0] in f.lib['public.skipExportGlyphs']:
    make_nonExp = False
else:
    make_nonExp = True

# let's change states
for g_name in f.selectedGlyphNames: # f.selection is deprecated
    
    g = f[g_name]
    
    if make_nonExp == True:
        if not g_name in f.lib['public.skipExportGlyphs']:
            f.lib['public.skipExportGlyphs'].append(g_name)
            non_exp.append(g_name)
	    
    elif make_nonExp == False:
        if g_name in f.lib['public.skipExportGlyphs']:
            f.lib['public.skipExportGlyphs'].remove(g_name)
            exp.append(g_name)
	    
    g.changed() # officially "updates" the glyph. g.update() is deprecated. 
    # doing the above on the "glyph" level should help it update in the UI
	
# print results
if exp != []:
    print("NEWLY SET TO EXPORT:")
    print(exp)
    
if non_exp != []:
    print("NEWLY SET TO NON-EXPORT:")
    print(non_exp)