[Python-Dev] PEP 3188: Implementation Questions (original) (raw)

Thomas Heller theller at ctypes.org
Sat Feb 27 18:20:01 CET 2010

Meador Inge schrieb:

On Fri, Feb 26, 2010 at 4:08 PM, Greg Ewing <greg.ewing at canterbury.ac.nz>wrote:

Meador Inge wrote:

3. Using Decimal keeps the desired precision,

Well, sort of, but then you end up doing arithmetic in decimal instead of binary, which could give different results. Even with the user-defined precision capabilities of the 'Decimal' class? In other words, can I create an instance of a 'Decimal' that behaves (in all operations: arithmetic, comparison, etc...) exactly as the extended double precision type offered by a given machine? Maybe the solution is to give ctypes long double objects the ability to do arithmetic? Maybe, but then we would have to give all numeric 'ctypes' the ability to do arithmetic -- which may be more than we want.

See issue 887237:

http://bugs.python.org/issue887237

-- Thanks, Thomas

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