How to test if a variable has a natural number?

[Dan Bishop]

Alexander Schmolck <a.schmolck at gmx.net> wrote in message news:<yfsznknjn5w.fsf at black132.ex.ac.uk>...
> pythonguy at Hotpop.com (Anand Pillai) writes:
> 
> > How about this...
> > 
> > from types import *
> > 
> > def natural(num):
> >     if num>0 and type(num) is IntType:
> >         return 1
> >     else:
> >         return 0
> 
> Nope. 
> 
> >>> natural(1L)
> 0

How about...

def natural(num):
   return num > 0 and num == long(num)

?