Michael Selik writes:
However, PEP 1 does not give instruction on how to evaluate whether that discussion has been completed satisfactorily.
That's because completion of discussion has never been a requirement for writing a PEP. Writing a PEP is a lot more effort than writing an email. The purposes of initiating discussions are 1. Avoid duplication. Nobody has encyclopedic knowledge of the hundreds of PEPs anymore, but the lists do. 2. Gauge feasibility of the proposal. Some are non-starters for reasons of "Pythonicity", others are extremely difficult to implement given Python internals or constraints like LL(1) syntax in the parser. 3. Gauge interest in the content of the proposal. If the protagonists think it's worth it after that, they write a PEP. Typically the discussion continues on list during the drafting.