PEP 285: Adding a bool type

[Guido van Rossum]

> [Guido]
> >>     5) Should operator.truth(x) return an int or a bool.  Tim Peters
> >>        believes it should return an int because it's been documented
> >>        as such.
> 
> [Ralph Corderoy]
> > Unlike Tim to produce such a poor reason.  Has he been paraphrased a
> > little too much?

[Tim]
> Not in Guido's eyes <wink>.  We don't need 3 equivalent ways to turn an
> arbitrary expression into a bool ("bool(x)" same-as "not not (x)" same-as
> "truth(x)").  *Especially* if str(bool) and repr(bool) produce 'True' and
> 'False', people have a legitimate need to make an arbitrary true/false
> expression produce 0 and 1 too, if only to preserve 0/1-based true/false
> output.  operator.truth() has always been the best way to do exactly that.
> Alternatives like "(boolexpr) + 0" and "(boolexpr) and 1 or 0" and "(0,
> 1)[boolexpr]" reek in comparison.

Tim must be missing something.  The obvious way to turn a bool b into
an int is int(b).  Having to import the obscure 'operator' module for
this purpose is backwards.  (IMO there's almost *never* a reason to
import that module anyway.)

--Guido van Rossum (home page: http://www.python.org/~guido/)