[Python-Dev] Mixing float and Decimal -- thread reboot (original) (raw)

Guido van Rossum guido at python.org
Sun Mar 21 00:52:42 CET 2010

On Sat, Mar 20, 2010 at 4:46 PM, Mark Dickinson <dickinsm at gmail.com> wrote:

On Sat, Mar 20, 2010 at 11:20 PM, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:

* Decimal and float really belong side-by-side in the tower, rather than one above the other. Neither of them is inherently any more precise or exact than the other. Except that float is fixed-width (typically 53 bits of precision), while Decimal allows a user-specified, arbitrarily large, precision; so in that sense the two floating-point types aren't on an equal footing.

But this doesn't really help deciding which should be positioned at the end does it? Both Fraction and Decimal can represent every float value (barring NaN/Inf). I wonder if we need to look at use cases or see what other languages do for guidance.

-- --Guido van Rossum (python.org/~guido)

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