Thank you for this very clear (and quick) explanation! :-) Cheers, Franck On 19 avr, 08:58, "Martin v. Loewis" <mar... at v.loewis.de> wrote: > # The reason that keywords are test nodes instead of NAME is that using > # NAME results in an ambiguity. ast.c makes sure it's a NAME. > argument: test [comp_for] | test '=' test [...]