On May 4, 2009, at 10:45 AM, kcrisman wrote: > Dear support, > > I assume this is known, but I am wondering whether it should be > treated as a bug, or whether someone using len() on lists should be > assumed to know it might then be operated on with Python /, not > Sage /, as opposed to the preparser catching this sort of thing.
len() is a Python builtin, which is a good indication that it will return Python types (especially when acting on a Python type). In fact, there's no way on the c-api level to return a Sage integer, as len() always returns a c long. This is similar to range returning a list of python ints. > sage: len([2,2])/len([2,3,4]) > 0 > > Thanks for any suggestions on what to do with this - right now I have > to do > > sage: Integer(len([2,2]))/Integer(len([2,3,4])) > 2/3 Yep, that's how to do it. (Note that only one of the numerator/ denominator needs to be cast, as coercion will cast the other.) sage: Integer(2)/int(3) 2/3 sage: int(2)/Integer(3) 2/3 sage: int(2)/int(3) 0 - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
