On Wed, Jun 18, 2008 at 1:47 AM, <[EMAIL PROTECTED]> wrote: >>>> 234 - 23234.2345 > -23000.234499999999 > > This is not correct by my calculations.
Python floating point operations use the underlying C floating point libraries which, in turn, usually rely on the hardware's floating point implementations. This Wikipedia article talks about how those values are usually stored and manipulated: http://en.wikipedia.org/wiki/IEEE_floating-point_standard So, which IEEE double precision floating point value would you like instead? As far as I understand it, these are your two choices: 'ba490c020f76d6c0' = -23000.234499999999 'bb490c020f76d6c0' = -23000.234500000002 Alternatively, investigate the Decimal module, but keep in mind that it can have the same sorts of issues, just on different numbers. Compare, for instance: >>> (1.0/3.0) * 3.0 1.0 >>> from decimal import Decimal >>> ( Decimal('1.0')/Decimal('3.0') ) * Decimal('3.0') Decimal("0.9999999999999999999999999999") >>> -- Jerry -- http://mail.python.org/mailman/listinfo/python-list
