[Python-Dev] Status regarding Old vs. Advanced String Formating (original) (raw)

Barry Warsaw barry at python.org
Fri Feb 24 23:02:55 CET 2012

On Feb 24, 2012, at 10:39 PM, Martin v. Löwis wrote:

It is a burden for some people to learn and remember the exact details of both systems and exactly how they differ. Having both in the stdlib hurts readability for such people. I would prefer that the stdlib only used {} formatting or if not that, that it only used the simple, hard-to-forget forms of % formatting (%s, %d, %f, without elaboration). If that issue was getting serious, I would prefer if the .format method was deprecated, and only % formatting was kept. I doubt this is as much of an issue as you think, though.

I personally prefer .format() these days, but I agree that it will be a long time, if ever, we see one of the styles getting dropped. I don't have much of a problem with the stdlib containing both styles as appropriate and preferred by the maintainer, as long as the module is consistent. Also, modules which provide a format-ish API should accept both styles, such as what logging currently does. (It's nice that logging also accepts PEP 292 $-strings too, don't forget about those. :)

-Barry

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