object types, mutable or not?

[Gregory Ewing]

I don't think it's very helpful to anyone to say that "everything
is an object", because "everything" is far too vague a term.
(It's not even close to being true -- there are plenty of concepts
in Python that are not objects.)

I think I would say something like "All data that a Python program
can manipulate comes in the form of things we call objects."
Then go on to give some examples of different kinds of objects --
integer objects, string objects, list objects, etc. And that
variables in Python don't contain objects, they just refer to
objects. Draw some diagrams with boxes and arrows.

-- 
Greg