Tuomas Suutari added the comment: On 29 March 2015 at 19:54, Serhiy Storchaka wrote: > I think that Decimal is not needed for Fraction.__format__ (and I'm not sure > that issue23602v4.patch is correct).
Of course it's not needed. I'm using it to avoid re-implementing all the various formatting variations that can be controlled with the fill/align/sign/width/,/precision/type parameters (https://docs.python.org/3/library/string.html#formatspec). IMHO those should be supported as they are with floats and Decimals. > The correct way to format Fraction as fixed-precision decimal is to use > Fraction.__round__() or similar algorithm. The implementation can look like: > > f = self.__round__(prec) > i = int(f) > return '%d.%0*d' % (i, prec, abs(f - i) * 10**prec) Why this would be more correct than delegating the rounding (and formatting) to Decimal.__format__? (Then we just have to make sure that we have enough precision in the decimal context we're operating in. That's what I got wrong in the previous round.) ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23602> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
