Question about None

John Yeung gallium.arsenide at
Sat Jun 13 17:49:34 EDT 2009

On Jun 13, 5:22 pm, "Rhodri James" <rho... at>
> Such an understanding would be clearly wrong in the context
> in which we were talking (and denotational semantics is a
> branch of category theory, which is not specific to computer
> science if you don't mind).  If None is nothing, then it can't
> be a string, int, float or anything else, because they're all
> something.

I appreciate your explanation, and your politeness.

And I accept your answer, as well as Steven's and Paul's for that
matter.  I still think it is understandable (and people may choose to
understand in a condescending way, if they wish) that someone might
not get the difference between what you are saying and the statement
that all elements of the empty set are floats.  I mean, what's in the
empty set?  Nothing.  But you've said that floats are something.  How
is it that nothing is something?

Please, I do not wish to extend this thread.  My last question was
rhetorical.  It's not a challenge.  I accept your answer, as well as
the others.  To be clear, I find it very intuitive that None does not
match the other types.  But just as the devil seems to have plenty of
advocates, I guess I am a naive person's advocate, of sorts.  (I must
stress I'm not the OP's advocate, nor do I consider him naive.)


More information about the Python-list mailing list