[Python-Dev] PEP 3101: floats format 'f' and 'F'

Guido van Rossum guido at python.org
Wed Jul 16 19:38:24 CEST 2008


On Wed, Jul 16, 2008 at 10:30 AM, Eric Smith
<eric+python-dev at trueblade.com> wrote:
> 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.

Fine with me to change %F as well -- after all that's where the
misunderstanding comes from. (More and more I'm beginning to think it
was my mistake. :-)

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)


More information about the Python-Dev mailing list