On 10 January 2012 17:40, [email protected] < [email protected]> wrote:
> > > On 10 January 2012 17:22, Jim Jewett <[email protected]> wrote: > >> On Mon, Jan 9, 2012 at 12:59 PM, [email protected] >> <[email protected]> wrote: >> > Or maybe it's considered not pythonic to use >> >> > int(1.3) >> >> > instead of >> >> > from math import floor >> > floor(1.3) >> >> > But I doubt that... >> >> Your hint is too subtle -- having int truncate non-integers was a >> regret that caused the introduction of __index__ (for "as an integer") >> on things that really are integers. >> >> So now there really are several numeric types that won't (or at least >> won't always) respond to int, precisely because you should specify >> what sort of rounding you want. Sympy probably should follow that >> policy, and is therefore doing the right thing. (That said, I won't >> get involved if you want some sort of context with default decisions. >> The Decimal module may provide useful guidance.) >> > The stuff about __index__ is completely new for me and it seems quite > interesting. Could you explain a bit more why it is a problem when int > truncates floats or point me to some resource on the question? > I found it here http://www.python.org/dev/peps/pep-0357/ So in conclusion it's a good thing that int(expression) does not work. Rounding should be as explicit as possible. > >> -jJ >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/sympy?hl=en. >> >> > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
