o.O Very nice
On Fri, Feb 10, 2012 at 8:58 PM, Arnaud Delobelle <arno...@gmail.com> wrote: > On 10 February 2012 06:21, Ian Kelly <ian.g.ke...@gmail.com> wrote: >>>>>> (3219 + 99) // 100 * 100 >>> 3300 >>>>>> (3289 + 99) // 100 * 100 >>> 3300 >>>>>> (328678 + 99) // 100 * 100 >>> 328700 >>>>>> (328 + 99) // 100 * 100 >>> 400 >>> >>> Those are all rounded up to the nearest 100 correctly. >> >> One thing to be aware of though is that while the "round down" formula >> works interchangeably for ints and floats, the "round up" formula does >> not. >> >>>>> (3300.5 + 99) // 100 * 100 >> 3300.0 >> > > I'm surprised I haven't seen: > >>>> 212 - (212 % -100) > 300 > > Here's a function that: > * rounds up and down > * works for both integers and floats > * is only two operations (as opposed to 3 in the solutions given above) > >>>> def round(n, k): > ... return n - n%k > ... >>>> # Round down with a positive k: > ... round(167, 100) > 100 >>>> round(-233, 100 > ... ) > -300 >>>> # Round up with a negative k: > ... round(167, -100) > 200 >>>> round(-233, -100) > -200 >>>> # Edge cases > ... round(500, -100) > 500 >>>> round(500, 100) > 500 >>>> # Floats > ... round(100.5, -100) > 200.0 >>>> round(199.5, 100) > 100.0 > > -- > Arnaud > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
