[Python-Dev] Comparing date+time w/ just time (original) (raw)

Guido van Rossum guido at python.org
Sat Oct 22 15:58:16 CEST 2005

On 10/22/05, skip at pobox.com <skip at pobox.com> wrote:

With significant input from Fred I made some changes to xmlrpclib a couple months ago to better integrate datetime objects into xmlrpclib. That raised some problems because I neglected to add support for comparing datetime objects with xmlrpclib.DateTime objects. (The problem showed up in MoinMoin.) I've been working on that recently (adding rich comparison methods to DateTime while retaining cmp for backward compatibility), and have second thoughts about one of the original changes.

I tried to support datetime, date and time objects. My problems are with support for time objects. Marshalling datetimes as xmlrpclib.DateTime objects is no problem (though you lose fractions of a second). Marshalling dates is reasonable if you treat the time as 00:00:00. I decided to marshal datetime.time objects by fixing the day portion of the xmlrpclib.DateTime object as today's date. That's the suspect part. When I went back recently to add better comparison support, I decided to compare xmlrpclib.DateTime objects with time objects by simply comparing the HH:MM:SS part of the DateTime with the time object. That's making me a bit queazy now. datetime.time(hour=23) would compare equal to any DateTime with its time equal to 11PM. Under the rule, "in the face of ambiguity, refuse the temptation to guess", I'm inclined to dump support for marshalling and comparison of time objects altogether. Do others agree that was a bad idea?

Agreed.

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

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