Sergey B Kirpichev <skirpic...@gmail.com> added the comment:
> I'd prefer to keep the code simplicity It's not going to be complicated so much and algorithms are well known, but I see your point. > and the speed for small inputs here Speed loss is not so big, 10-20%. > Python's needs aren't the same as SymPy's needs or SAGE's needs So, for which needs it will serve? Sorry, I can't suggest an application, which does use builtin Fraction's (not sure if even SAGE uses them, as a fallback). SymPy doesn't, for sure (but it could - it's PythonRational class uses same optimizations, except for g == 1 branches in _add/_sub, I think). There is one exception I've found: stdlib's statistics module uses Fraction's in the _sum() helper, exactly in a paradigm "sum a lot of values". > not all of the fractions.Fraction use-cases involve summing lots of values > with incompatible denominators. No need for a lots of values (i.e. 1000): denominator of the sum will grow very fast, that why modern CAS use modular GCD algorithms, for example. > Could you give some idea of the crossover point for a single addition? $ ./python -m timeit -r11 -s 'from fractions import Fraction as F' -s 'a=F(10,31011021112)' -s 'b=F(86,11011021115)' 'a + b' 20000 loops, best of 11: 12.4 usec per loop $ ./python -m timeit -r11 -s 'from patched import Fraction as F' -s 'a=F(10,31011021112)' -s 'b=F(86,11011021115)' 'a + b' 20000 loops, best of 11: 12.5 usec per loop ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43420> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
