Mailman 3 August 2004 - Edu-sig

Re: [Tutor] what? (late nite entertainment) (*)
by Gregor Lingl March 25, 2005

March 25, 2005

Now: early morning corrections ... Alfred Milgrom wrote: > Hi Gregor: > > Hard to work out what is what :) as there seems to be a typo in one > line of your code: > > if x[z]: x[z*z:n:z]=y[z*z:n:z] > > (At least it doesn't work on my machine with Python 2.2) > Yeah, I had the idea when playing around with some new features of Python 2.3, as I do sometimes late at night - before shutting down my computer. This one I found at: http://www.python.org/doc/2.3.3/whatsnew/section-slices.html and I looked for an example for use of "assignment with extended slices" ... > Also the subroutine breaks for n = 1 or less. > Maybe you need a line at the start to say > if n <2 : return [0] > what() was intended to generate all primes less than n. (In fact it's an implementation of the sieve of Eratosthenes). The bugs came not only from not beeing interested in primes less than 2 ;-) but also from beeing a little tired already. Sorry. I think the following version repairs that - and hopefully uses less obfuscating variable names (which in fact originally was part of the "riddle"): def primes(n): sieve, zeros = range(n), [0]*n sieve[:2]= 0,0 i = 1 while i*i < n: if sieve[i]: sieve[i*i:n:i]=zeros[i*i:n:i] i += 1 return [p for p in sieve if p] Regards, Gregor >

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Re: Re: [Edu-sig] How to introduce test-driven development?
by Kent Johnson Aug. 20, 2004

Aug. 20, 2004

Peter, Thanks for the suggestion! I'll have to play around with doctest myself, I have never used it. BTW the course is open to the public. Anyone in the vicinity of Merrimack, NH, US who wants to learn Python, go to http://www.merrimack.k12.nh.us/ to register! Kent > > From: Peter Fröhlich <phf(a)cs.ucr.edu> > Date: 2004/08/19 Thu PM 11:45:46 EDT > To: Kent Johnson <kent37(a)tds.net> > CC: <edu-sig(a)python.org> > Subject: Re: [Edu-sig] How to introduce test-driven development? > > Hi all! > > On Aug 19, 2004, at 18:43, Kent Johnson wrote: > > > I am going to be teaching introductory Python programming in an adult > > education program this fall. (Finally! I wanted to do this in the > > spring but it didn't work out.) I want to introduce the students to > > unittest and test-first programming but I am not sure when and how to > > do this. > > I'd suggest introducing doctest instead of pyunit. It's simpler, no > classes, just like the interpreter, etc. Worked well for me when I > introduced it to my students. > > BTW, please be sure to let the list know how your course is going. I am > planning to introduce some Python in an (essentially) social science > class next year. :-) > > Peter > -- > Peter H. Froehlich <><><><><><> http://www.cs.ucr.edu/~phf/ > OpenPGP: D465 CBDD D9D2 0D77 C5AF 353E C86C 2AD9 A6E2 309E > >

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How to introduce test-driven development?
by Kent Johnson Aug. 20, 2004

Aug. 20, 2004

Hello, I am going to be teaching introductory Python programming in an adult education program this fall. (Finally! I wanted to do this in the spring but it didn't work out.) I want to introduce the students to unittest and test-first programming but I am not sure when and how to do this. - using unittest requires a bit of understanding of classes unless I want to wave my hands quite a bit - beginning programs may not have much to test, especially if they are heavily oriented toward console I/O I'm tempted to just wing it - wait for a student to bring a problem that lends itself to testing, then demonstrate unittest and TDD. But I am interested in other ideas :-) Thanks, Kent

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story re a python class (in a police station)
by Kirby Urner Aug. 8, 2004

Aug. 8, 2004

Here's an article about an open source class I co-taught in June, which included some Python programming: http://www.oregonlive.com/search/index.ssf?/base/news/1090963968123690.xml?a rgus?News -- may prompt for zip, dob, gender. Kirby

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collection of exercises
by gen2n Aug. 8, 2004

Aug. 8, 2004

There are a lot of tutorials and references on the Net, but I somehow much miss some examples/exercises that are in my view necessary for full and deep understanding of explained matter. I have in mind exercises for non-university-people where are practised either single structures of a language or generally understood exercises that could be then solved in any language. Do you know any? Pavel Kosina

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RE: [Edu-sig] Re: Teaching graphics with Python
by Kirby Urner Aug. 2, 2004

Aug. 2, 2004

> But getting it down to its essentials, the following runs, and provides a > sphere primitive that insists on being blue. Just upgraded to the latest VPython and tested your code (in Windows so far, will move to Linux box next). Works great. Wondering where you're getting this info re atexit, for example, given there's no documentation. From digging in the source code you say? > import cvisual Had to change the above to: import visual.cvisual as cvisual # (just a path issue) > import time > import atexit > > def __waitclose(): > while not cvisual.allclosed(): time.sleep(0.05) > atexit.register(__waitclose) > > scene = cvisual.display() > > class sphere (cvisual.sphere): > def __init__( self,*args,**keywords): > cvisual.sphere.__init__(self) > self.color=(0,0,1) self.color=(160/255.,32/255.,240/255.) # Purple! > self.complete_init( self, self, > 1, scene, None) > scene.background = (1,1,1) # white background anyone? > s=sphere() It's great to be able to finally do this VPython stuff interactively in the native IDLE without problems (at least for the most part). The Download page is more explicit now about what the default install will do, e.g. overwrite any existing Numeric with version 23.0, plus mentions how to get back to where Python default boots to a shell, not to the editor (my preference, easily restored). Kirby

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RE: [Edu-sig] Re: Teaching graphics with Python (was Introductoryhighschool programming)
by Arthur Aug. 1, 2004

Aug. 1, 2004

> > Arthur: > > As I say, there is no API documented for the facility of subclassing > > brought to VPython through the Boost implementation. > > > > And I suspect not as much attention was given to developing this as an > > intuitive API as there might have been, and wouldn't be surprised if > there > > is no intention of the VPython project to document it. Or at least to > > give documentation of it any priority. > > These go together. By not documenting any API, they're free to give more > thought to changing it later. Once documented, it's harder to keep > revamping it. I hope that is the direction they are going. Just don't know. Bruce has disappointed me before. He tends to like to control the flow of information in ways that I am not totally comfortable with. There are smart guys who know there are plenty of other smart (and smarter) guys out there. And then there are the guys who *always* seem to worry about talking over peoples heads. One of the things I love about the Open Source community is the struggle to keep up. > > Until there's some documentation, I guess it's very unsafe (in the sense > of > future code breakage) to build any real codebase on the new subclassing > features. I wouldn't worry about it too much. I don't see much changing other than possibly the initialization routine. With modern text editors... Art

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RE: [Edu-sig] Re: Teaching graphics with Python (was Introductoryhighschool programming)
by Arthur Aug. 1, 2004

Aug. 1, 2004

> > import cvisual > > import time > > import atexit > > > > def __waitclose(): > > while not cvisual.allclosed(): time.sleep(0.05) > > atexit.register(__waitclose) > > > > scene = cvisual.display() > > > > class sphere (cvisual.sphere): > > def __init__( self,*args,**keywords): > > cvisual.sphere.__init__(self) > > self.color=(0,0,1) > > self.complete_init( self, self, <------- TWO SELVES? > > 1, scene, None) > > > > s=sphere() Yeah. TWO SELVES. I get to this by mechanically following some of what is being done in the primitives.py module of the new VPython distribution. As I say, there is no API documented for the facility of subclassing brought to VPython through the Boost implementation. And I suspect not as much attention was given to developing this as an intuitive API as there might have been, and wouldn't be surprised if there is no intention of the VPython project to document it. Or at least to give documentation of it any priority. I suspect that from the focused concerns of the VPython project, the facility is seen - at least at this point - as a byproduct of the use of Boost, rather than something they want to "confuse" their users with. Doesn't mean I'm not free to confuse their users with it ;). Art

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Re: Introductory high school programming
by Darren Payne Aug. 1, 2004

Aug. 1, 2004

See topics & msgs below to put my comments in context. I have been a member of this group for quite a while and content myself with reading the interesting things people have to say. Now I would like to add some of my experiences for others to consider. I teach computing to high school students in Australia (Sydney, NSW actually). I currently work in a "selective" school - US readers would understand this better as magnet school. Entry is gained via a battery of tests & positions offered. A few years ago I completed post grad study in gifted ed - at the end was invited to write a 2 day unit to be used in the university's gifted program. I have taken up this offer and based it on work by Jeff Spence (Canadian guy on exchange in my hometown a few years back) Anyway - I have been using Java and have reasonably successfully taught an introduction to Java - as a first language - to 10 and 11 year old children. This year I decided I would introduce my year 7 classes to Java. Now, after one term (10 weeks), I fear it is just too difficult. In essence, the more Java I learn the less I like Java. The decision to go with Java was encouraged by my current yr12 class whom last year were determined to learn a "real" language AKA C++. I compromised and "taught" them Java. Only one of these students has put in enough effort to establish any level of skill with the language. I really wanted to show them Python. Last year (as well - in parallel to yr12) I started teaching Python as a first language to my yr9 (now yr10) class - they loved it and I enjoyed teaching it. Re Scheme; my yr12 class also do an option involving different paradigms - one of these is the functional paradigm. So I teach Haskell. I really like it, I like the way it makes me think. Because the students can be examined on either Hskell or Scheme (Lisp) I also show them some Scheme - but prefer Haskell becasue no reverse Polish notation and no brackets! In summary, I have found Python far and away to be the best language for high school students. It is powerful, easy to use, has clear simple syntax that doesn't "get in the way", is extendable with loads of other modules, has an active developer community, is open source so I can burn it CD and legally give it to kids to take home and so much more. Perhaps best of all it teaches the major, MODERN CONCEPTS in programming and these are easily transferred to other languages. I don't like Java (read this like "tiggers don't like Java" - I have a 3 yr old and 4 old!)- it is all just hype and we have all been suckered in. Compiler errors are a hassle for students - interpreted is much better during learning & development of programs. Being forced to use OO for even trivial programs puts too much overhead in the way of learning to program. Python overcomes this because OO is optional - you don't have to use it with trivial programs. Anyway - enough from me at this point. Hope this offers a semi empirical flavour to the discussion. regards P.S. - consider Python Programming for absolute beginner by Michael Dawson as a text. Darren Payne Hurlstone Agricultural High School > > > Today's Topics: > > 1. Introductory high school programming class - > Python or > TeachScheme (Joseph Ehlers) > 2. Python for High School Students (Garret > McGraw) > 3. RE: Introductory high school programming class > - Python > orTeachScheme (Kirby Urner) > 4. RE: Introductory high school programming class > - Python > orTeachScheme (Liow, Dr. Yihsiang) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 5 May 2004 20:48:25 -0500 > From: "Joseph Ehlers" <ehlersjp(a)msn.com> > Subject: [Edu-sig] Introductory high school > programming class - Python > or TeachScheme > To: <edu-sig(a)python.org> > Message-ID: > <BAY4-DAV64OgRGkQ6mB00001262(a)hotmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > I'm trying to propose an introductory computer > programming class for high school students. I do > not have a programming background so I will be > learning the language just like the students. > Through my research I came across Python. It sounds > great - easy to learn, teaches thinking skills, and > is fun. I was set to go with Python then I came > across the TeachScheme project which also sounds > great - it too is easy to learn, teaches thinking > skills and comes with lots of curriculum. I have a > few questions and I'm hoping this group can shed > some light on this issue. > > 1. Is one better than the other (Python vs. > TeachScheme) to teach high school novices > programming skills, thinking skills, language, and > keeping their attention so I can then have an > audience for a second, more advanced programming > class? > > 2. I've looked at "How to Think Like a Computer > Scientist", it looks very doable for a novice and > "Python Programming for the Absolute Beginner" > (Premier Press) looks like a lot of fun. Is there > any other curriculum for high school students out > there? > > 3. Is it possible to teach a semester of > TeachScheme and a semester of Python or is that > overkill on the basics and not doing justice to > either program? > > I appreciate your assistance. >

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Re: Teaching graphics with Python (was Introductoryhighschool programming)
by Arthur Aug. 1, 2004

Aug. 1, 2004

> I wanted to thank you for this stereoscopic feature in VPython, and > suggestion that I use it. Just thought I'd mention that VPython 3.0 has been released last week. This version is mostly a behind the scenes revamp of the code. VPython now uses the Boost Python library to expose Vpython's cvisual C++ code to Python. Among other things this allows one to directly subclass cvisual primitives in pure Python. Currently this is an undocumented facility as to VPython. But getting it down to its essentials, the following runs, and provides a sphere primitive that insists on being blue. import cvisual import time import atexit def __waitclose(): while not cvisual.allclosed(): time.sleep(0.05) atexit.register(__waitclose) scene = cvisual.display() class sphere (cvisual.sphere): def __init__( self,*args,**keywords): cvisual.sphere.__init__(self) self.color=(0,0,1) self.complete_init( self, self, 1, scene, None) s=sphere() Seems to me this facility will open up interesting new possibilities in having fun with VPython/cvisual. PyGeo for example could now decide to more truly wrap the cvisual library, as opposed to using it - through Vpython - as a rendering back-end. > > My slides are here: > http://www.4dsolutions.net/oscon2004/ (might be some minor problems if > viewed in Windows, not sure (tried to make it work well in both, but > kept finding little discrepancies going back and forth, and did all > last minute editing on the Linux side)). Looks super. Art

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RE: [Edu-sig] Re: Teaching graphics with Python (was Introductoryhighschool programming)
by Arthur Aug. 1, 2004

Aug. 1, 2004

> -----Original Message----- > From: Kirby Urner [mailto:urnerk@qwest.net] > Sent: Sunday, August 01, 2004 3:23 AM > To: 'Arthur' > Subject: RE: [Edu-sig] Re: Teaching graphics with Python (was > Introductoryhighschool programming) > > > But getting it down to its essentials, the following runs, and provides > a > > sphere primitive that insists on being blue. > > > > Yes, you asked for blue. VPython seems less able than VRML or OpenGL in > general to support textures and like that. Probably because it's > *supposed* > to be a simple API. Yes. I have missed transparency most particularly. But David Scherer explained to me early on that the naïve view I had that adding transparency in VPython would only involve allowing access to the alpha channel in OpenGL is mistaken. To do it right, based on the way the cvisual code draws, there is all kinds of depth testing necessary to add something like transparency correctly. And he wasn't interested in implementing it in a half-ass manner. But obviously there are no limitations on what you can do in developing an API for exporting VPython objects to Povray. If you access the povexport files at the vpython site, you will see an example of adding wood textures in povray from Vpython. But for your work, you can now simply add your developed povray export code to objects you subclass from cvisual, so that you have the possibility of modeling interactively in VPython, and exporting for more refined rendering in povray in a manner fully under your control, and without re-inventing any wheels. Art

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