On 3/9/07, Collin Winter <[EMAIL PROTECTED]> wrote: > On the subject of datetime enhancements, I came across an SF patch > (#1673403) the other day that proposed making it possible to compare > date and datetime objects. Quoting from the patch summary: > > """ > Comparing a date to a datetime currently throws an exception. This makes no > sense. In what way is: > > datetime(2006, 1, 1, 0, 0, 0) < date(2007, 1, 1) > > not a perfectly reasonable and well-defined comparison? Throwing an > exception here violates the "Principle of Least Surprise" to a considerable > degree. > > Obviously some slight ambiguity arises if the date and the datetime differ > only in the time part. There are two sensible responses in this situation > that I can see: > > Treat dates as if they have a time-part of midnight. This is my preferred > solution, and it is already what the datetime module does, for example, > when subtracting two dates. > > Treat dates as if they refer to the entire day, i.e. if the date and > datetime differ only in the time part then they are equal. This is > consistent but becomes confusing in other situations such as when > subtracting dates. > """ > > Any thoughts on this?
One solution that just occurred to me -- and that skirts the issue of choosing an interpretation -- is that, when comparing date and datetime objects, the datetime's .date() method is called and the result of that call is compared to the original date. That is, datetime_obj < date_obj is implicitly equivalent to datetime_obj.date() < date_obj Seems a ready-made use case for that method. Collin Winter _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
