[Python-Dev] Emit a BytesWarning on bytes filenames on Windows

["Martin v. Löwis"]

> As quoted above, deprecation of the bytes version of the API sounds
> fine to me, but isn't this going to run into the usual objections from
> the "we need bytes for efficiency" crowd?  It's OK with me<wink> to
> say "in this restricted area you must convert to Unicode", but is that
> going to fly with that constituency?

I don't think this "we need bytes for efficiency" crowd actually exists.
We are talking about file names here. The relevant crowd is the
"we need bytes for correctness", and that crowd focuses primarily on
Unix. It splits into the "we only care about Unix" crowd (A), the
"we want correctness everywhere" crowd (B), and the "we want portable
code" crowd (C). (A) can accept the deprecation. (B) will support it.
Only (C) might protest, as we are going to break their code, hence
the deprecation period.

Regards,
Martin