for / while else doesn't make sense

[Ben Bacarisse]

Ian Kelly <ian.g.kelly at gmail.com> writes:

> On Mon, May 23, 2016 at 2:09 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Are you saying that the Egyptians, Babylonians and Greeks didn't know how to
>> work with fractions?
>>
>> http://mathworld.wolfram.com/EgyptianFraction.html
>>
>> http://nrich.maths.org/2515
>>
>> Okay, it's not quite 4000 years ago. Sometimes my historical sense of the
>> distant past is a tad inaccurate. Shall we say 2000 years instead?
>
> Those links give dates of 1650 BC and 1800 BC respectively, so I'd say
> your initial guess was closer.

Right, but this is to miss the point.  Let's say that 4000 years have
defined 1/3 to be one third, but Python 3 (as do many programming
languages) defines 1/3 to be something very very very very close to one
third, and *that* idea is very very very very new!  It's unfortunate
that the example in this thread does not illustrate the main problem of
shifting to binary floating point, because 1/2 happens to be exactly
representable.

-- 
Ben.