[Python-Dev] PEP 461: Adding % formatting to bytes and bytearray -- Final, Take 2

Antoine Pitrou solipsis at pitrou.net
Sun Feb 23 22:37:45 CET 2014

On Sun, 23 Feb 2014 12:42:59 -0800
Ethan Furman <ethan at stoneleaf.us> wrote:
> On 02/23/2014 03:33 AM, Antoine Pitrou wrote:
> > On Sat, 22 Feb 2014 17:56:50 -0800
> > Ethan Furman <ethan at stoneleaf.us> wrote:
> >>
> >> ``%a`` will call :func:``ascii()`` on the interpolated value's :func:``repr()``.
> >> This is intended as a debugging aid, rather than something that should be used
> >> in production.  Non-ascii values will be encoded to either ``\xnn`` or ``\unnnn``
> >> representation.
> >
> > Why is "%a" here? I don't remember: was this discussed before?
> > "Intended as a debugging aid" sounds like a weak justification to me.
> https://mail.python.org/pipermail/python-dev/2014-January/131808.html
> The idea being if we offer %a, folks won't be tempted to abuse __bytes__.

Which folks are we talking about? This sounds gratuitous.

Also, I don't understand what debugging is supposed to be in the
context of bytes formatting. You print debugging output to a text
stream, not a bytes stream. And you certainly *don't* print debugging
output into a wire protocol.



More information about the Python-Dev mailing list