It's not possible to skip the code generation part because a resulting converter is always compiled from the code written under the hood. Could you please share what is your concern about this? I'd really like to better understand it!

JFYI: it's possible to skip running "gen_converter" method, it's possible to just use "execute" -- it runs "gen_converter" under the hood: c.group_by( c.item(0) ).aggregate({ c.item(0): c.reduce(c.ReduceFuncs.Sum, c.item(1)) }).execute([ (0, 1), (0, 2), (0, 3), (1, 10), (1, 12), ])

  Out[5]: [{0: 6}, {1: 22}]

The downside is that you won't be reusing the converter.