Jeffrey Yasskin added the comment: Mark: Coming from C++, I don't have any intuition on static vs. class methods. It might be strange to write MyRationalSubclass.from_float() and get a Rational back, but it might also be strange to write a subclass with a different constructor and get an error. So go ahead.
Guido: It would be a shame to decide that classes shouldn't inherit from ABCs for performance reasons. Issue 1762 tracks the problem, but I haven't paid much attention to it. Let's see if we can fix that before using virtual inheritance for Rational. Special-casing ints in the constructor sounds like a good idea, and we can cache the results of .numerator and .denominator in _add, etc, without having to change the overall logic, which should save 2μs (leaving 1 on the table). It could be useful to declare a private constructor that expects ints that are already in lowest terms, sort of like decimal._dec_from_triple(). __add__ couldn't use it directly, but __abs__ could. I don't think it's too late to rename one of the classes. I'm using "RationalAbc" inside of rational.py to refer to numbers.Rational, which is one reason I was positive on adding a suffix to the ABCs, but renaming this class is fine with me too. __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue1682> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
