[Edu-sig] Teaching Python as a gateway to teaching whatever...

[Kirby Urner]

>Why don't you compare Python with a true competitor such as Scheme? 
>
>It has the same advantages as Python, has been around much longer, is
>regular, and is already taught at hundreds of colleges and high schools. 
>
>-- Matthias

In theory, we have a lot of latitude regarding how to craft 
a course, even at the high school level.

Given that Python incorporates a lot of features common to 
other languages, it's useful for developing some ideas and 
skills with an eye towards introducing other languages as well.

I always appreciated my intro classes in college for 
precisely this approach:  part of the aim was to open our 
eyes to the huge number of languages out there and something
about their history as well.  I got some hands-on experience
with a sampling, and really enjoyed that.

In sum, I think a dynamite intro to programming course might
use Python as a base of operations within which to develop 
concepts Mr. Elkner was listing etc. (branching, looping, 
resursion, procedure, class/subclass/object, data types, 
arrays), and then get into something of the rich heritage a 
contemporary student inherits, if willing.

Speaking of the tree structure, how languages tend to grow
on trees is useful information.  Show the LISP family tree, 
give some sense of its nomenclature and current state. 
Download DrScheme and introduce some of the basics.  Do 
the same with a LISP (which has a loop construct and relies
far less on recursive strategies -- unless in the hands of
a Schemer).

Talk about SmallTalk and Squeak -- dive into it for a few
days.  

Maybe use Jython as an intro to Java.  Then talk pure Java.
Use this as a bridge back to C/C++ and, coming full circle,
touch on CPython as C code, and how to extend same.

Did I forget to mention Perl?  Tsk.  And what about Haskell
and ISETL and FORTRAN and APL and...   obviously it's up to 
the teacher what to cover in finite time.  But what's so cool 
about getting your intro today, vs. X years ago, is you've got 
a lot of free resources and GUI versions of just about all 
of the above.  It's a rich and well-supplied environment, all 
there, ready to be explored.

What I'd like to see in a next generation of programmers is 
less propensity to indulge in language wars of any kind --
especially of the pointless kind, as if the aim were to make
the "competition" simply go away and to envision an "ideal
world" wherein everyone eventually sees the light and programs
in language X (whatever language X might be).  So many religions
have made this mistake, and I think the less of them for it.

So when we teach Python as a first language, I _hope_ the 
attitute isn't going to be to encourage snobbery and "my 
language is better than yours" attitudes.  On the contrary, 
_all_ the languages are part of your common heritage, and 
you can use any of several to leverage your understanding
of all the others.

To me, this is what any "introduction to programming" is really
about, at least initially.  It's about learning some of the 
basic concepts (and that includes knowing something about how
computers work) and it's about getting some overview and feel
for the evolutionary picture, the zoology, the taxonomy.  It's
not about studying just one animal in the zoo the whole day,
and ignoring all the other creatures.

And finally, in an even "grander" scheme of things, I'm looking
at ordinary non-computer languages in the same overview, starting
with the math notations, with all their varied syntax and symbols.
Math languages have had a big influence in computer language 
from the start -- except I think it's increasingly a two way 
street, with the bidirectional aspect becoming clearer by the
day.  So I'm all for a hybrid of computer science and concrete
mathematics which draws examples of what to program from the 
math texts, and which shows students how language X is managing
to implement some of the same ideas as embodied in math 
notation Y (boolean algebra is a good place to start, then 
maybe loops of the kind signified by Sigma and Pi, then gcd
and lcm... etc. etc. 

See: http://www.inetarena.com/~pdx4d/ocn/overcome.html -- which
is mostly addressed to math teachers, as I don't believe in 
necessarily putting computers on one side of a bureaucratic 
turf divide and math courses on the other -- leaving serious 
math teachig to the graphing calculator crowd seems a serious
misallocation of resources in my book).

I'll try to summarize with a course outline, drawn off the top 
of my head and on the spot:

             Introduction to Computer Programming

   Cardinality (numbers as names)

       Looking at serial numbers, social security numbers, license
       plate alpha-numeric strings, and talking about the 
       pervasiveness of databases in our culture (record keeping)
       Videoclip possibilities:  airline reservations, talking 
       heads re their jobs, clips from the movie 'Brazil' (welcome 
       to information retrieval -- metropolis/bureaucracy/art deco)
       -- I recommend short vidclips from your school's DVD juke 
       box wherever appropriate (won't continue listing them here,
       as your school probably doesn't have a repository in any 
       case). http://www.inetarena.com/~pdx4d/ocn/cardinality.html

   Ordinality (numbers in order)

       quick review of integers and real numbers, with an eye towards
       data types and the computer concepts of floating point, double
       precision, big numbers, integers, negatives numbers (ties forward
       to later mention of binary representations, 2s complement etc).
       Emphasize the importance of operators > < = in an ordered 
       system, plus the appearance of operations such as + / * - 
       (quick mention of groups, fields and rings, just as an aside
       and the fact that these are topics in algebra)

   Positional Notation and Bases

       talk about base 10, other bases, with strong links to the abacus 
       as the artifact that makes all this rather easy to think about.
       Start introducing Python, including a module with lots of precoded
       methodes having to do with bases and base conversion.  Show the
       binary strings corresponding to integers.

   Binary representation

       ASCII    
       more use of Python to show bytes as 8-bits, some discussion 
       of the history of ASCII, leading up to a discussion of:

       Unicode
       visit the Unicode website and take a look at some of the PDFs 
       showing the symbols/glyphs covered by this system.  Talk about 
       powers of 2, and the space of permutations depending on how 
       many bits in a string (2^N).

       Review:  http://www.inetarena.com/~pdx4d/ocn/intro0.html

  Computer Languages 

        History of Computers and Computing Devices
        
        Start with the abacus, move through navigation as a principle 
        challenge for humans and the development of knowledge and 
        instrumentation in that domain, and ballistics.  The importance
        of ciphers, codes, cryptology should be emphasized, with this
        thread picked up in WWII.  Discuss Alan Turing at Bletchy Park,
        the German Enigma codes.  Use Python to play with the rotor 
        module.  Clubhouse codes.  Mention Ada Byron and some of the 
        controversy around her 'first computer programmer' title.
        http://www.teleport.com/~pdx4d/adaessay.html

        Talk about Grace Hopper and COBOL, and the idea of a compiler.
        Overview of Compiler, Interpreter, Bytecodes, Virtual Machine,
        libraries, linking, Assembly Language, chips as having 
        instruction sets, registers, access to short and longer term
        memeory via bus, RISC, MIX, MMIX (talk about Knuth's multi-
        volume classic without trying to make this a college course 
        about it).

  Getting into it with Python

        Overview

        Discuss its lineage/heritage, how it's a VHLL coming out after
        a long history of language evolution, and how we'll therefore
        be using it to study earlier life forms and other branches of
        the evolutionary tree, down to live/evolving languages in
        contemporary use.

        http://www.inetarena.com/~pdx4d/ocn/cp4e.html

        Data Types and Data Structures, Conversion
            Strings, floats, integers, long numbers
            Types, attributes, lists, tuples, dictionaries

        Managing Program Flow
            Branching, looping, recursion, calling and 
            returning, mapping (includes list comprehension)

        Functions and Methods
            parameters, functions as objects with attributes,
            passing functions as parameters (optional, by name)

        Classes/Subclasses and Objects
            [this is where I usually swap in Polyhedra as objects
            and/or Groups as objects, after some simpler examples]            

        Managing with Modules
            Scope issues, namespaces, importing, documenting

 << SNIP >>

Kirby