Are you making that comment by speculating or by having looked at the Obnam codebase? I'm not a Python developer, but I've looked at the Obnam code enough to have written a replacement crypto plugin for it. AFAICT, if Obnam was holding Python wrong, it's too hard to hold it right.
I haven’t looked at the code, but I hope someone who has been using Python for 20+ years knows how to write and use it properly... so yeah, I’m inclined to agree with you.