Guido van Rossum wrote:
Decimals are just a different way of displaying Rationals and depending on their preset precision show a different behaviour in numeric operations.
Not necessarily. If decimals are used for (in-memory) representation, they can't represent all rationals.
I know, that's what I wanted to say with "depending on their preset precision"; if you have a decimal with precision 2 then 1/3 will come out as "0.33" -- my point was that by implementing a Rational type instead of a decimal type we can have all semantics of decimals by simply subclassing the Rational type. This setup will be more flexible than choosing one of the many different variants of "how to add two decimal numbers" (e.g. calculator style, with hidden extra digits, with truncation, mathematical rounding, (one of the various) financial rounding modes, etc.). -- Marc-Andre Lemburg CEO eGenix.com Software GmbH ______________________________________________________________________ Consulting & Company: http://www.egenix.com/ Python Software: http://www.lemburg.com/python/