Modifying Class Object

Stephen Hansen apt.shansen at
Tue Feb 9 16:27:06 CET 2010

On Mon, Feb 8, 2010 at 10:35 PM, Alf P. Steinbach <alfps at> wrote:

> Right.
> "pass by value" is a lower level notion.
> And as you show below, in the paragraph marked [1], it can be used to
> describe call by sharing very succinctly and precisely, just as I did... ;-)

No. There's nothing at all succinct or precise about either "value" or
"reference" when speaking of programming languages, and using both together
just compounds that. They are loaded words. The phrase "call my value where
value is an object reference" is not clear, not obvious, not helpful. It
requires far too much explanation of every single word there, depending on
the background of who you are speaking to, to explain how it does not
exactly use any of the words in a way which the person may be expecting, and
making sure they understand that it does not imply anything that those words
usually imply.

I'm not even going to bother further-- I shouldn't have to begin with-- your
entire post is full of arguments with no more weight then, "I say this means
that, and its clearer" with absolutely no regard for the fact that all of
these words have weight and meaning to the world outside of your head.

Python has objects, and objects have names. Objects are never copied
implicitly, and objects can be referred to by many names in many places,
thus you may share those objects as you see fit. Some objects you may
change, some objects you may not. An object exists so long as someone has a
name for it. Period, end of line.

That's the mental model and passing model that is valid in Python. There are
no "copyable references", because a reference is a 'thing' and copying it is
an action. In Python there are simply objects. That's where the abstraction
begins and ends.

What is so obvious, precise, succinct and clear to YOU is mixing loaded
terms with a implications and semantic expectations from countless other
languages and sources in computer science. If you want to think of things
that way in your head, then by all means, do so.

But it doesn't make it right, and further arguing is clearly just not going
to do any good. You're insisting on using imprecise terminology common to
other languages in complicated ways together to describe very simple things.

Python has objects, objects are given various names.

It helps no one to try to artificially create an abstraction above that
which the language provides as you are doing.

I've heard that before, and have no idea why, nor any real interest in
>> solving it: I don't want to read cpl via Usenet, and prefer to read it as a
>> mailing list. Somewhere between Gmail->> <
>>>'s usenet server->the world, some people don't seem to
>> get my posts. Yet it shows up on some news servers, not others.
>> No idea. Nothing I know of can solve it.
> Not sure, but perhaps it's possible to mail directly to gmane?

I participate with the community via python-list; I take no responsibility
for the deficiency of any particular usenet server which may or may not
mirror python-list accurately. Usenet's a fuzzy thing like that, with all
the servers cross-sharing and messages bouncing around. I have no need for
its complexity and unbounded freedom.

I'm subscribed to a mailing list, albeit a high-volume one. That its
cross-mirrored with a usenet group is something I have no control over, and
usenet is inherently beyond control. Its great that Gmane provides a means
of making usenet discussion groups accessible as mailing lists, but I don't
see any reason to bother.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the Python-list mailing list