[Python-Dev] Not-a-Number (was PyObject_RichCompareBool identity shortcut)
tjreedy at udel.edu
Sun May 1 20:45:06 CEST 2011
On 5/1/2011 7:27 AM, Nick Coghlan wrote:
> However, I did find Terry's suggestion of using the warnings module to
> report some of the floating point corner cases that currently silently
> produce unexpected results to be an interesting one. If those
> operations issued a FloatWarning, then users could either silence them
> or turn them into errors as desired.
I would like to take credit for that, but I was actually seconding
Alexander's insight and idea. I may have added the specific name after
looking at the currently list and seeing UnicodeWarning and
BytesWarning, so why not a FloatWarning. I did read the warnings doc
more carefully to verify that it would really put the user in control,
which was apparently the intent of the committee.
I am not sure whether FloatWarnings should ignored or printed by
default. Ignored would, I guess, match current behavior, unless
something else is changed as part of a more extensive overhaul. -f and
-ff are available to turn ignored FloatWarning into print or raise
exception, as with BytesWarning. I suspect that these would get at lease
as much usage as -b and -bb.
So I see 4 questions:
1. Add FloatWarning?
2. If yes, default disposition?
3. Add command line options?
4. Use the addition of FloatWarning as an opportunity to change other
defaults, given that user will have more options?
Terry Jan Reedy
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