On 08/25/2015 02:22 PM, Alexander Belopolsky wrote:

On Tue, Aug 25, 2015 at 5:04 PM, Carl Meyer wrote:

...

I can't imagine how raising an exception on invalid times only if a non-default sentinel value is given for a flag that is _new in PEP 495_ could possibly break 4000 lines of existing datetime tests.

OK, so datetime module itself will never set fold=-1. In the list below, can you mark the methods that need to be patched to check the fold attribute in your preferred design:

If `fold=None` is present /when attempting to create a datetime/ that is ambiguous or invalid, an exception is raised /at that moment/ meaning that a datetime with `fold=None` /will never exist/. `fold=None` /will not be the default/.

datetime.__add__ no datetime.__eq__ no datetime.__format__ no datetime.__ge__ no datetime.__gt__ no datetime.__hash__ no datetime.__le__ no datetime.__lt__ no datetime.__ne__ no datetime.__new__ YES datetime.__radd__ no datetime.__reduce__ no datetime.__reduce_ex__ no datetime.__repr__ no datetime.__rsub__ no datetime.__str__ no datetime.astimezone no datetime.combine YES (could have a time instance with fold=None) datetime.ctime no datetime.date no datetime.dst no datetime.fromordinal no datetime.fromtimestamp no datetime.isocalendar no datetime.isoformat no datetime.isoweekday no datetime.now no datetime.replace YES datetime.strftime no datetime.strptime only if `fold=` is allowed datetime.time no datetime.timestamp no datetime.timetuple no datetime.timetz no datetime.today no datetime.toordinal no datetime.tzname no datetime.utcfromtimestamp no datetime.utcnow no datetime.utcoffset no datetime.utctimetuple no datetime.weekday no

-- ~Ethan~