Howto engage Python contributors in the long term?

I don’t really understand this – maybe when you say “CoC” you’re thinking of something different than me? To me, the Update on moderation post has all the key features that define a CoC: it gives concrete guidance on acceptable and unacceptable behavior, describes potential consequences for the latter, and is written down so people know what to expect, or can critique it if necessary. It’s also in many ways a bad CoC: limited scope, limited range of behavior covered, didn’t get much review by the community, the enforcement mechanisms are pretty blunt (e.g. there’s no appeal), probably could have more positive encouragement like you suggest, etc. But that’s because it was written in a scramble while we actually had “single-use accounts created behind Tor with a temporary email address” posting. Dealing with this was way more painful/controversial/slow than it would have been if we’d written something like this down ahead of time.

Moderating is incredibly hard when you don’t know the rules you’re enforcing and don’t know if the community will have your back on any given decision.