There can only be one TopDict in an OpenType font, whether CFF or CFF2; plus in the latter, TopDict INDEX and Names INDEX are gone, just the one TopDict is left. Most of the time, one simple wants to get to that single TopDict instance. So instead of doing this: topDict = font['CFF '].cff.values()[0] one can alternatively do this now: topDict = font['CFF '].cff[0]