[Edu-sig] More Python in the Classroom

[kirby urner]

So I taught Python to 8th graders again this morning, as I've been doing for
the last 10-11 weeks.  I used the "dog theme", introducing a simple Dog
class, per recent thread with Andre, in IDLE:

class Dog:
    def __init__(self, name):
        self.name = name

and using it to create instances dog1, dog2 (Fido and Rover).  Then I went
back and added a bark method.  The point was to introduce the class/instance
distinction.  I use this wrap about a house blueprint, and an architect
using it to build an instance in Beaverton and Mt. Tabor (local
neighborhoods):  one blueprint, two actual houses (or house objects).  Then
I go back to my dogs.

All this is a prelude to reinforcing "dot notation" i.e. now that we have
dog.name and dog.bark(1), it makes more sense to discuss a first collection
type:  lists.  We gradually build up the following function, in several
iterations, with kids entering at their workstations, watching my projected
version up front:

def askme(howmany=3):
    dogs = []
    for i in range(howmany):
        thedog = raw_input("Dog's name? ")
        dogs.append(thedog)
    dogs.sort()
    return dogs

I was thinking of Arthur's suggesting to reinforce the distinction between
'print' and 'return'.  A first draft of the above function simply prints,
doesn't sort.  Then I talk about returning a value versus echoing it to
screen (essentially what 'print' does -- not to a printer (one girl asked me
about that)).  Also, we start without any argument, looping 3 times.  Adding
howmany is a separate step, making it default to 3 yet another iteration.

I like the way IDLE lets me "copy down" i.e. continually re-edit a given
function, gradually adding to it.  I'm projecting in 20 pt type or so, using
Comic Sans (looks friendly).

This is all very basic stuff, not breaking much new ground.  I'm
experimenting with how to introduce "dot notation" which I regard as very
important.  Really, it should be incorporated into standard math notations
in a more integral way.  object.verb(args) and object.property just makes a
lot of sense as a standard way to notate.

"""

In my view, the mathematicians have been too slow to acknowledge dot
notation as a legitimate contribution to mathematics proper.  The math books
don't allow that A.b(z) is a good way to organize thinking, A being an
object of some type, perhaps inheriting from parent types, and b being a
method, accepting argument(s) z.  v1.add(v2) is as smart a way to signify
vector addition as v1 + v2, plus makes it clear where the methods belong:
in the class definitions.

When math students are asked to actually number crunch with these
mathematical objects (quaternions say), dot notation is what they encounter,
more often than not.  And yet there's this artificial line that gets drawn:
"that's just the computer's way of expressing things, not really a math
notation" is the party line (I'm not in that party).
"""

Source:  http://mail.geneseo.edu/pipermail/math-thinking-l/2006-February/000982.html


Another recent mention of Python in education (today, by me):
http://mathforum.org/kb/thread.jspa?threadID=1337652&tstart=0

Kirby
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.python.org/pipermail/edu-sig/attachments/20060223/0a70bde5/attachment.html