[Python-ideas] Python Numbers as Human Concept Decimal System

[Chris Angelico]

On Sat, Mar 8, 2014 at 1:59 AM, Stephen J. Turnbull <stephen at xemacs.org> wrote:
> Seriously, as one data point, I don't think having more "human"
> representations encourages me the think of floating point results as
> the product of arithmetic on real numbers.  I don't think anybody who
> knows how tricky "floating point" arithmetic can be is going to be
> fooled by the "pretty eyes" of a number represented as "2.0" rather
> than "1.99999999999999743591".

Fair enough. I just remember reading, back in my really REALLY early
days with GW-BASIC, an explanation of why 3.2# (the hash made it
double-precision) came out as whatever-it-did. Went into a full
explanation of the nature of binary floating point, and the issue was
forced to your attention because just about _any_ value that wasn't a
neat multiple of a (negative) power of two would do that.

You can lead a programmer to docs, but you can't make him understand.

ChrisA