[Python-Dev] New math functions

[Neal Becker]

Mark Dickinson wrote:

> On Tue, Feb 12, 2008 at 1:52 AM, Raymond Hettinger <python at rcn.com> wrote:
> 
>> Also, it would be useful to have a new method, float.is_integer().  This
>> would be better than the current approach where we make the
>> test:  if x == floor(x).
>>
> 
> How common is this test?  Given the inexact nature of floating-point
> arithmetic, checking whether a float is exactly an integer seems like
> something that one might actually want to discourage, just like comparing
> two floats for equality.
> 
> Also, what about having float.is_finite, as a quicker way to spell "not
> isinf(x) and not isnan(x)"
> 
> +1 on making these methods of float;  they're fundamental properties.
> 
> Mark

Yes, and I don't know if this was mentioned, but should add to complex also.

isfinite (complex_x):
        return isfinite (x.real) and isfinite (x.imag)