ACCEPTED: PEP 285

[Delaney, Timothy]

> From: Terry Reedy [mailto:tejarex at yahoo.com]
>
> > Clarification
> >
> >     This PEP does *not* change the fact that almost all object types
> >     can be used as truth values.  For example, when used in an if
> >     statement, an empty list is false and a non-empty one is true;
> >     this does not change and there is no plan to ever change this.
> 
> almost? all?  I am under the impression that 'if x:' is universally
> valid, and consider that one of the good features of Python's prime
> dichotomy system.

Something of the form:

class Klass:

    def __nonzero__(self):
        raise NotImplementedError

will fail an if x: test ...

Tim Delaney