> So, after reading the above comments, I think we may end up with
> following changes:
>  * restore the "bytes-to-bytes" codecs in the "encodings" package
>  * then create new helpers on bytes objects (either
>    ".transform()/.untransform()" or ".encodebytes()/.decodebytes")

I would still be opposed to such a change, and I think it needs a PEP.
If the codecs are restored, one half of them becomes available to
.encode/.decode methods, since the codec registry cannot tell which
ones implement real character encodings, and which ones are other
conversion methods. So adding them would be really confusing.

I also wonder why you are opposed to the import statement. My
recommendation is indeed that you use the official API for these
libraries (and indeed, there is an official API for each of them,
unlike real codecs, which don't have any other documented API).