On Mon, Oct 12, 2009 at 4:05 PM, Anand Balachandran Pillai <abpil...@gmail.com> wrote: > > > On Mon, Oct 12, 2009 at 4:02 PM, Anand Balachandran Pillai > <abpil...@gmail.com> wrote: >> >> >> On Mon, Oct 12, 2009 at 3:47 PM, Anand Chitipothu <anandol...@gmail.com> >> wrote: >>> >>> On Mon, Oct 12, 2009 at 2:42 PM, Baiju Muthukadan <ba...@muthukadan.net> >>> wrote: >>> > http://bitcheese.net/wiki/nopython >>> > >>> > Don't start a flame war now, please ;) >>> >>> 2.3 - 3.4 and 2/3.0 in Python, Ruby and Haskell interpreters. >>> >>> $ python3.0 >>> Python 3.0.1 (r301:69597, Feb 14 2009, 19:03:52) >>> [GCC 4.0.1 (Apple Inc. build 5490)] on darwin >>> Type "help", "copyright", "credits" or "license" for more information. >>> >>> 2.3 - 3.4 >>> -1.1000000000000001 >>> >>> 2/3.0 >>> 0.66666666666666663 >>> >>> $ irb >>> >> 2.3 - 3.4 >>> => -1.1 >>> >> 2/3.0 >>> => 0.666666666666667 >>> >> ^D >>> >>> $ ghci >>> GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help >>> Loading package base ... linking ... done. >>> Prelude> 2.3 - 3.4 >>> -1.1 >>> Prelude> 2/3.0 >>> 0.6666666666666666 >>> Prelude> Leaving GHCi. >>> >>> It looks like number of decimal digits printed are 17 in Python, 16 in >>> Haskell and 15 in Ruby. >>> >>> Is there any way to change that behavior in Python? >> >> Not in the interpreter AFAIK. In code, use Decimal type. >> >> import decimal >> >>> x=decimal.Decimal('2.3') >> >>> y=decimal.Decimal('3.4') >> >>> x-y >> Decimal("-1.1") >> >> I am not however a fan of the decimal module since it uses strings as the >> base type. > > You do end up with quirks like the following however. > >>> x=decimal.Decimal('2.3') >>>> y=decimal.Decimal('3.4') >>>> z=x-y >>>> z > Decimal("-1.1") >>>> str(z) > '-1.1' >>>> z>(2.2-3.4) > True > > ;-) > > Perhaps the "bitchy" blogger has a point w.r.t floating point handling.
Not really. That is problem with floating point computation and not with Python. Even that is same in Ruby. $ irb >> 1.1 > (2.2-3.4) => true >> ^D Anand _______________________________________________ BangPypers mailing list BangPypers@python.org http://mail.python.org/mailman/listinfo/bangpypers
