Thank you Jonathan, performance is one of the various reasons I prefer join to assembles strings, than, say, triple-quote dedent'ed f-strings or concatenation. It also plays well syntaxically, even though there is still a little room for improvement. For example, in PHP implode('-', array(2, 'a')) returns '2-a', and now that I think of it, it's the only thing i regret from php's stdlib... And assembling a string like that really looks like a common problem programmers face every day of their journey...
The chuacong.site design for extratools documentation is really beautiful ! I found the smartplit function but no smartjoin. On my side I have requested comments on a PR in the boltons repo already, let's see if they find refutation before proposing a smartjoin implementation to extratools. https://github.com/mahmoud/boltons/pull/197
Would you recommend to release it on its own ? Ie. from implode import implode ?