[Python-Dev] PEP 460 reboot (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Mon Jan 13 18🔞10 CET 2014

On Mon, 13 Jan 2014 08:36:05 -0800 Ethan Furman <ethan at stoneleaf.us> wrote:

On 01/13/2014 08:09 AM, Antoine Pitrou wrote: > On Mon, 13 Jan 2014 07:59:10 -0800 > Guido van Rossum <guido at python.org> wrote: >> On Mon, Jan 13, 2014 at 3:41 AM, Antoine Pitrou <solipsis at pitrou.net> wrote: >>> What is the use case for embedding a quoted ASCII-encoded representation >>> in a byte stream? >> >> It doesn't crash but produces undesired output (always, not only when >> the data is non-ASCII) that gives the developer a hint to think about >> encoding to bytes. > > But why is it better to give a hint by producing undesired output (which > may actually go unnoticed for some time and produce issues down the > road), rather than simply by raising TypeError?

You mean crash all the time? I'd be fine with that for both the str case and the bytes case. But's probably too late to change the str case, and the bytes case should mirror what str does.

No, there's a good reason for the str case: it's that every Python object should have a working str (for debugging, REPL use, etc.). So bytes has a str too and that's why "%s" % (some_bytes_object) succeeds.

Conversely, though, str needn't and shouldn't have a bytes, so there's no good reason for b"%s" % (some_str_object) to succeed.

(moreover, I don't think "we did it wrong here" should be a good reason for doing it wrong there too)

Regards

Antoine.

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