tough-to-explain Python

[Wesley Chun]

On Jul 7, 1:04 pm, kj <no.em... at please.post> wrote:
> I'm having a hard time coming up with a reasonable way to explain
> certain things to programming novices.
>     :
> How do I explain to rank beginners (no programming experience at
> all) why x and y remain unchanged above, but not z?
>     :
> What do you say to that?
>
> I can come up with much mumbling about pointers and stacks and
> heaps and much hand-waving about the underlying this-and-that, but
> nothing that sounds even remotely illuminating.
>
> Your suggestions would be much appreciated!


kj,

i don't have too much to add to everyone else's response except to
describe how i deal with this. i teach Python courses several times a
year and realized long ago that conveying the concept of mutable vs.
immutable is a key to getting up-to-speed quickly with Python as well
as helping beginners.

so, although techically, this is more of an intermediate topic rather
than "beginner" material, i still teach it anyway, with the hopes of
producing better Python programmers out of the gate, and hopefully,
less frustrated ones. in fact, i dedicated an entire chapter (4) in
Core Python Programming just to address this important issue. to top
it all off, i end this module in the class by giving 2 quizzes, just
to make sure they understood what i just told them. i put the 1st one
online, so if you're curious, the PDF is at http://roadkill.com/~wesc/cyberweb/introQuiz.pdf
... the 2nd quiz is harder and involves the discussion of the
differences between shallow and deep copies. so yes, not very beginner-
ish stuff, hence the reason why i (re)named my course "Intro
+Intermediate Python".

finally, rather than the "paper tag" or alex's hotel statue analogy, i
just say that variables are like Post-It® or sticky notes on
objects. i can tag objects anytime, tag objects more than once, remove
tags, or switch them to another object, etc.

just my $0.02,
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
    http://corepython.com

wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com