[Pythonmac-SIG] Numeric Q: How to get DBL_MAX, etc. in Python?

[Michael Hudson]

"Louis M. Pecora" <pecora@anvil.nrl.navy.mil> writes:

> In C there are platform-specfic, floating-point constants as follows defined in float.h,
> 
> /* The largest double precision # */
> DBL_MAX                 (* (double *) __double_max)
> 
> /* The accuracy of double precision */
> #define DBL_EPSILON     (* (double *) __double_epsilon)
> 
> /* The smallest double precision # */
> #define DBL_MIN         (* (double *) __double_min)
> 
> Where do these reside in Python?  

Nowhere.

> I have looked over my Python manuals and done a Google search, but
> can't find any reference to them or float/double limits outside of
> some threads online that are requesting the same as me, but no
> answers.  Are there standard Python functions or globals that return
> these values for the platform one is operating on?

Nope.  Obviously writing a C extension to expose these shouldn't be
too hard... (although making them constants is inevitably a bit broken
-- DBL_EPSILON varies as the rounding mode does, for example).

> Any help appreciated. Thanks.

Well, not sure this counts.

Cheers,
M.

-- 
  > So what does "abc" / "ab" equal?
  cheese
         -- Steve Holden defends obscure semantics on comp.lang.python