Hi Fabien,
Sorry for the late answer, this post just popped up now on my forum dashboard.
Thanks for reporting that issue! (And the related issue here: BUG with Python node). We already managed to reproduce some Jedi-related errors/crashes but were not yet able to fix those.
As far as I can tell, downgrading jedi to an older version (e.g. 0.9.0) may sometimes help prevent further crashes.
Marcel