[Datetime-SIG] PEP-495 - Strict Invalid Time Checking

Carl Meyer carl at oddbird.net
Tue Aug 25 23:50:33 CEST 2015


On 08/25/2015 03:47 PM, Alexander Belopolsky wrote:
> 
> On Tue, Aug 25, 2015 at 5:44 PM, Carl Meyer <carl at oddbird.net
> <mailto:carl at oddbird.net>> wrote:
> 
>     On 08/25/2015 03:36 PM, Alexander Belopolsky wrote:
>     >
>     > On Tue, Aug 25, 2015 at 5:28 PM, Carl Meyer <carl at oddbird.net <mailto:carl at oddbird.net>
>     > <mailto:carl at oddbird.net <mailto:carl at oddbird.net>>> wrote:
>     >>
>     >> My answer is "only in those same locations where the fold attribute
>     >> would otherwise be checked in order to resolve an ambiguity."
>     >
>     >
>     > This includes utcoffset() which is used in datetime.__eq__.  What should
>     > __eq__ do if utcoffset() raises AmbiguousTimeError?  Unpatched, it will
>     > propagate the exception resulting in for example x in [y, x, x, x]
>     > raising an error whenever y happened to be fold=-1 ambiguous.  Is your
>     > code prepared to handle  AmbiguousTimeError whenever you search for a
>     > date in a list?  Does it check for fold != -1 before adding a date to a
>     > list?
> 
>     This is a good question. I can see two defensible choices:
> 
> Pick one and try to defend it.  In the face of ambiguity ...

I already did that.

"while (2) is tenable for `__eq__`, it doesn't have such a
neat resolution for inequality comparisons and probably other cases
either, so (1) is probably best."

and earlier in (1), "This would be entirely fine with me."

Carl

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: <http://mail.python.org/pipermail/datetime-sig/attachments/20150825/4ca910e2/attachment.sig>


More information about the Datetime-SIG mailing list