[Edu-sig] Edu-sig Digest, Vol 39, Issue 2

[Arthur Siegel]

On Mon, 2006-10-02 at 16:04 -0700, kirby urner wrote:
> > Anyway, I would advocate the "as opposed to" be integrated into such a
> > presentation.
> >
> > Art
> >
> Actually *duplicating* a piece of memory (wasteful?), to make the same
> contents reside elsewhere (why?), with its own handles, is considered
> a semi-esoteric move in Python, not something you'd necessarily need
> right out of the box.

In my mind, it is not a matter of needing copy right out of the box.
And that is the argument I keep running into when making this general
case - that teaching "copy" - in any form -  early overemphasizes
something that is "semi-esoteric". And I understand that point.

Except that mutable/non-mutable is cognitively more than semi-esoteric
for the uninitiated.  While there certainly is nothing in the least
esoteric about the list data-type or the assignment operator. 

The argument I keep making and for which I cannot seem to find any
takers, is that essential to explaining/understanding assignment of a
list to a name, is understanding in the negative - i.e., what it is not.
We are still just teaching basic assignment with regard to a list, and I
maintain that doing so effectively should in part be done in the
negative. What it is not silhouetting better what it is.

Art