[Python-Dev] PEP 3101: floats format 'f' and 'F' (original) (raw)

Eric Smith eric+python-dev at trueblade.com
Wed Jul 16 19:30:24 CEST 2008

Guido van Rossum wrote:

On Wed, Jul 16, 2008 at 7:35 AM, Eric Smith <eric+python-dev at trueblade.com> wrote:

Does anyone know why 'F' is the same as 'f'? Wouldn't it make more sense to either drop it, or make it convert the exponent to upper case (like 'E' and 'G')? Compatibility with %-formatting is the only reason I can think of to keep up, but I get the sense we've given up on an automatic conversion from %-formatting to str.format(). Plus, I can find no uses of '%F' in the standard library. My best guess as to why 'F' is the same as 'f' is that somebody (could've been me :-) thought, like several others in this thread, that %f never prints an exponent. I agree that making it emit an 'E' when an exponent is used is the right thing to do. Do it now!

It shares code with %-formatting. Change that, too? I couldn't find any occurrences of %F in the stdlib. Not that that's the entire universe, of course.

The change is slightly less elegant if I don't change %-formatting, but still doable, especially if the betas don't get cut today.

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