Something or Nothing^H^H^H^H^H^H^HEmpty

[Anders J. Munch]

"Magnus Lie Hetland" <mlh at vier.idi.ntnu.no> wrote in message
news:slrnab9s50.6g8.mlh at vier.idi.ntnu.no...
> In article <3cb3fbc0$0$78808$edfadb0f at dspool01.news.tele.dk>, Anders
> J. Munch wrote:
> >Pythons truth values are not "Something or Nothing".  The phrase seems
> >to have caught on following Laura's post, but I believe it is
> >misleading.
>
> I don't.
>
> >[] and {} are objects,
>
> Yes, as are None and 0.

The important part is that they are _mutable_ objects.  The identity of each
instance is by itself important information.

>
> > they are objects with identity, and they are
> >mutable objects.  They are empty, but they are by no means "nothing".
>
> Would you call them false? Would you call 0 empty? It's an intuitive
> way of explaining the concept, not a precise one.

With true~something and false~nothing, "if history:" in my example asks if
something was passed for the optional argument.  I'd call that intuitive.
Intuitively my function is correct as written.  Hence true~something and
false~nothing guides my intuition poorly.

And no, I wouldn't call 0 empty, although there is a reasonable association
in that 0 is the cardinality of an empty container.  I would call this stuff
"considered false" or "treated as false in Python".

As for intuitive ways of explaining concepts: Examples, examples, examples.
Accept no substitute.

and-that-goes-for-newsgroup-postings-too-ly-y'rs, Anders