[Larry Hastings <la...@hastings.org>]
> Guido just stopped by--we're all at the PyCon 2019 dev sprints--and we had
> a chat about it. Guido likes it but wanted us to restore a little of the
> magical
> behavior we had in "!d": now, = in f-strings will default to repr (!r), unless
> you specify a format spec. If you specify a format spec it will always default
> to format. And naturally if you specify an explicit conversion function (!r
> !s !a)
> it will use that.
>
> This makes !f irrelevant, so we're removing it.
>
> Here's the thinking: 99% of the time the user will just use {foo=}, and for
> that
> you want repr. After that, 0.99% of the time the user will want a format spec
> that applies directly the value. It's exceedingly unlikely that someone will
> want a format spec, but want it to apply to repr(value) and not value itself.
> So
> that's possible (f'{foo=!r:20}'). But the default behavior is the most common
> case at every step.
+1. Perfect! I'm one of the 0.99% who will frequently use this to
display floats, and really wants them to show as "0.99%" rather than
"0.9913499340289%".
BTW, that Guido person has made enough decent contributions by now
that I think he should be asked whether he wants to become a core dev!
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
