[Python-Dev] PEP 461 - Adding % and {} formatting to bytes (original) (raw)

Paul Moore p.f.moore at gmail.com
Fri Jan 17 17:06:55 CET 2014

On 17 January 2014 15:50, Eric V. Smith <eric at trueblade.com> wrote:

For #3, hopefully this "additional work" on the 3.x side would just be to add, to each class where you already have a custom format used for b''.format(), code like:

def formatascii(self, fmt): return self.format(fmt.decode()).encode('ascii')

For me, the big cost would seem to be in the necessary documentation, explaining the new special method in the language reference, explaining the 2 different forms of format() in the built in types docs. And the conceptual overhead of another special method for people to be aware of. If I implement my own number subclass, do I need to implement format_ascii?

My gut feeling is that we simply don't implement format() for bytes. I don't see sufficient benefit, if %-formatting is available.

Paul.

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