[Python-Dev] Re: Revamping Python's Numeric Model

[Moshe Zadka]

[Martin v. Loewis]
> It's not inherently wrong. It just points out an omission in the PEP:
> it doesn't talk about the meaning of number literals.

That's right -- but I did mean that floating-point literals will be
inexact.

> Since the new
> model is going to follow algebraic principles more closely, I had
> expected that
> 
>   0.333333333 == 333333333 / 1000000000
> 
> where, as I understand the proposal, the right-hand side is an exact
> number (so 0.333333333*3 would be 999999999 / 1000000000).
> 
> One of the more-frequent questions on python-help is confusion about
> floating-point numbers, e.g. why is the result of 1.99+4.99 printed
> as 6.9800000000000004; users often report that as a bug.

That's one thing my PEP is not meant to help with -- floating point
numbers will remain hard. Hopefully, people will use them less often
when they'll have rational arithmetic.

-- 
Moshe Zadka <sig@zadka.site.co.il>