Meador Inge schrieb: > Hi All, > > Recently some discussion began in the issue 3132 thread ( > http://bugs.python.org/issue3132) regarding > implementation of the new struct string syntax for PEP 3118. Mark Dickinson > suggested that I bring the discussion on over to Python Dev. Below is a > summary > of the questions\comments from the thread. > > Unpacking a long-double > =================== > > 1. Should this return a Decimal object or a ctypes 'long double'? > 2. Using ctypes 'long double' is easier to implement, but precision is > lost when needing to do arithmetic, since the value for cytpes 'long > double' > is converted to a Python float. > 3. Using Decimal keeps the desired precision, but the implementation would > be non-trivial and architecture specific (unless we just picked a > fixed number of bytes regardless of the architecture). > 4. What representation should be used for standard size and alignment? > IEEE 754 extended double precision?
A variant of 2. would be to unpack into a ctypes 'long double', and extend the ctypes 'long double' type to retrive the value as Decimal instance, in addition to the default conversion into a Python float. -- Thanks, Thomas _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
