[Datetime-SIG] Another round on error-checking
tim.peters at gmail.com
Mon Aug 31 22:38:53 CEST 2015
>> The easiest way out of this particular puzzle is, I believe, to say
>> that two datetimes identical except for `fold` do _not_ compare equal.
>> `fold` breaks the tie in the obvious way (the one with fold==1 is
> I am afraid you are right, but proving that we will not break naive (fold
> unaware) programs will be harder in this case. Let me think some more
> about this.
> Meanwhile, would you see any problem with not(x - y) not implying x == y?
Which is another puzzle :-( It's very intentional now that
dt1 == dt2 if and only if dt1 - dt2 == timedelta(0)
Here's a related puzzle, if comparison used `fold` to break ties:
y = x + timedelta(0)
If x had first=1, y will have fold=0, and then x != y.
In all, maybe it's better to leave __hash__ slightly broken.
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