Postfix/Prefix Operators (++,--)

[John Roth]

"Peter Hansen" <peter at engcorp.com> wrote in message
news:3EE149EF.73C7373F at engcorp.com...
> John Roth wrote:
> >
> > "Peter Hansen" <peter at engcorp.com> wrote in message
> > news:3EE0D19C.7D7FFCA0 at engcorp.com...
> > > Joshua Marshall wrote:
> > > >   >>> c = 1
> > > >   >>> a = c++
> > > >   >>> a
> > > >   1
> > > >   >>> c
> > > >   2
> > >
> > > Except that that violates a fundamental aspect of Python, which
while
> > > I can't describe it in the best technical terms as I don't ever
work
> > > at the compiler level, could be said as "you are rebinding a name
(c)
> > > without using an assignment statement".
> >
> > Well, let's see. The "def", "class" and "import" statements all
(re)bind
> > names. So do several of the builtin functions (setattr() comes to
mind
> > immediately.)
>
> I figured my inability to use the proper technical terms would cause
> trouble.  I think Joshua has the best perspective: the fundamental
> aspect of Python which is being violated here is that of not rebinding
> things in an expression.  The examples you give are not expressions so
> I think they still fit in the Python mould.  I'll comment on Joshua's
> exception in a response to his message...

But setattr() is used in expressions! However, I agree with you in
general, setattr() is an exceptional case.

John Roth
>
> -Peter