Alexander Belopolsky <[EMAIL PROTECTED]> added the comment: On Sat, Nov 15, 2008 at 5:08 AM, Mark Dickinson <[EMAIL PROTECTED]> wrote: > > Mark Dickinson <[EMAIL PROTECTED]> added the comment: > >> timedelta / <float or int> should be disallowed in true division mode. > > I don't understand this; why should the division mode affect > division operations involving timedeltas at all?
Here is how I think about this: timedeltas are integers in units of time. For simplicity, let's assume we always express timedeltas in microseconds (us), so timedeltas are things like 1us, 2us, etc. As with integers, we can define true division (/) and floor division (//) so that 3us/2us = 1.5 and 3us//2us = 1. Note that the result is dimensionless. Similarly, you can divide timedeltas by dimensionless integers: 3us/2 = 1.5us and 3us//2 = 1us. However in python you cannot have a timedelta representing 1.5us, so timedelta(0, 0, 3)/2 should be en error. In order to have a timedelta/int true division, we would need to have another type floattimedelta which would be a floating point number in units of time. > The meaning of "/" is unaffected by the division mode for float/float or > float/int; why should timedeltas be any different? Because they are integers. If we had a floattimedelta type that would store timestamp as a float, its division would rightfully not be affected by the division mode. > I vote +1 for timedelta/timedelta and timedelta/float (regardless > of division mode). What do you vote timedelta/timedelta should produce in floor division mode: an int or a float? and what should timedelta/float produce: a timedelta or a float? _______________________________________ Python tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue2706> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
