[Python-ideas] Yet another sum function (fractions.sum)

[Stephen J. Turnbull]

random832 at fastmail.us writes:

 > Why exactly is an exception reasonable? If you don't want complex
 > numbers, don't take square roots of negative numbers. If you can't
 > handle complex numbers, you'll get an exception down the line anyway.

That's precisely why you want an exception: to terminate the
computation as soon as the unexpected condition can be detected.