On Sun, Mar 07, 2021 at 12:16:36PM +0000, Mark Dickinson wrote:
> but not the "incompatible denominators" part. :-) The typical use there is
> that those fractions have been converted from floats

But there is no limits to use Fraction's for input, e.g. there are
docstring examples for mean() and variance().  In that case (general one for
a summation) - common denominators is a very special situation.

> Thanks for the timings! So assuming that wasn't a specially-chosen best case example

No, but this will handle the first branch.

> > It's not going to be complicated so much
> For me, the big difference is that the current code is obviously correct

That may be fixed by keeping relevant references right in the code, not
in the commit message.  Python sources have many much more non-trivial
algorithms...