Mailman 3 April 2006 - Edu-sig

Fwd: Fractals
by kirby urner 28 Apr '06

28 Apr '06

---------- Forwarded message ---------- From: kirby urner <kirby.urner(a)gmail.com> Date: Apr 28, 2006 10:53 AM Subject: Re: [Edu-sig] Fractals To: "Jaime E. Villate" <villate(a)gnu.org> On 4/28/06, Jaime E. Villate <villate(a)gnu.org> wrote: > On Fri, 2006-04-28 at 07:17 -0700, kirby urner wrote: > > I also use Wolfram's stuff in Tk to introduce unpredictable complexity > > from simple (perhaps unknown) rules. > Can you give me a URL? I've done my own stuff in Tk/Maxima and I'm > interested to see what Wolfram has done. Slide 17 in this PDF, for what it looks like: http://www.4dsolutions.net/presentations/pythonicmath.pdf Here's a thread about source code: http://mail.python.org/pipermail/edu-sig/2004-May/003857.html Kirby

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Fractals
by kirby urner 28 Apr '06

28 Apr '06

So one of my high schoolers wants to use Python to understand Fractals? What should we do? Per my opener for Mandelbrot that time (a PowerPoint, done on short notice for Terry, when the originally scheduled talent bailed) I broke it down into sequences and their characteristics. Sequences may be reiterative, meaning they feed back into themselves (Fibonaccis the classic example). Sequences may be convergent, meaning they approach a value. Or divergent, meaning they go huge (more should be said). Or oscillatory (regular repeating sequence). Or chaotic, which is the "irrational number" like sequence: not divergent, not oscillatory, never settles down, never converges. Interesting. So then as an example of chaotic, we should import from cmath and simply explore the feedback loop z = z**2 + c for convergence or divergence. Actually, we don't really need cmath It's not that this loop is chaotic. It's that the boundary in between the convergent and divergent sequences it generates is chaotic. Two complex numbers, arbitrarily close together, may diverge in whether they converge or not, or on how fast they diverge (a source of color differences). >>> def seq(o=0j, z=1+1j): while True: yield o o = o**2 + z >>> g = seq() >>> for i in range(10): print g.next() # divergent! 0j (1+1j) (1+3j) (-7+7j) (1-97j) (-9407-193j) (88454401+3631103j) (7.81099614727e+015+6.42374081669e+014j) (6.05990163519e+031+1.0035162954e+031j) (3.5715362873e+063+1.21624200789e+063j) >>> g = seq(z=0.1+0.1j) >>> for i in range(10): print g.next() # convergent! 0j (0.1+0.1j) (0.1+0.12j) (0.0956+0.124j) (0.09376336+0.1237088j) (0.093487700481+0.123198705499j) (0.0935620291046+0.123035127359j) (0.093616210726+0.123022832334j) (0.0936293776353+0.123033862792j) (0.0936291289629+0.123039168003j) Kirby

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Re: [Edu-sig] Bootable Python CDs?
by Laura Creighton 28 Apr '06

28 Apr '06

In a message of Thu, 27 Apr 2006 08:18:49 EDT, "Paul D. Fernhout" writes: >Laura Creighton wrote: >> So bring-your-own distribution >> is the way to go. The only tricky thing is making sure that the >> students -- who want to save their own work on a CD -- actually >> do this properly. > >Wow, I had not even thought about students saving their work beyond to a >RAM disk for the session. Nor had I really thought they would take the >initiative to use a CD-ROM burner, but I guess those are common in school > >labs now? <snip> >Or does anyone carry around a few external USB CD-ROM burners with them >for kids to use to save their work? I bring exactly one. But I have a class size of about 15. They aren't that expensive. >USB Flash drives with 64MB these days are about $10 retail, so is it >possible to expect people to bring their own, or alternatively give them >out in class to keep (if it was a paid gig), to use to save their work >from done from the bootable CD? Do computer lab PCs in schools now >typically have at least one up-front USB ports for easy access? They do here in Göteborg, Sweden. I've thought about using USB sticks, but so far haven't found the motivation to change the way I already do things. >Of course, how important is it in in most cases for students to really >save their work from playing with Python for one session? Is this really >needed? I think so. But in addition to whatever else I am teaching at the time, I am also teaching 'how not to be a passenger in your own life'. So making tools you can use to _do_ or _find out_ something that matters to you is very important to me. 'It's your tool, you made it, and you get to keep it (and improve it)' is very much the message I want to get across. >And now, another thought, maybe if there was some easy way to save your >work to the Python site or some other web hosting service (gmail?) then >you would not need to worry about kids writing their stuff to CD or USB, >they could just run some magical Python application that would stash their >Python work on the network somewhere for later retrieval. I can see the >value of that as something to consider building into a Python educational >environment. When we tried this at the university, the pages ended up being full of the same sort of porn, viruses and root kits that made it necessary to wipe the machines in the first place. <snip> > >So, if you are going to a computer lab with network access > to the outside world (is this taken for granted these days in the USA?) I'm in Sweden. I wouldn't know what is available in the USA. <snip> >practice by some. > >--Paul Fernhout Laura Creighton

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Lightning compiler and doctest quizzes
by Andre Roberge 28 Apr '06

28 Apr '06

Inspired by Jeffrey Elkner's earlier posts about using doctest based quizzes to teach Python, I have done a fair bit of work on a little app I wrote a while ago called "Lightning compiler". It can be found on sourceforge, under lightning (https://sourceforge.net/project/showfiles.php?group_id=125834). Also, to quote from a previous message by Kirby Urner: "Python needs a more developed interactive teaching module: show some stuff, give students a command line, show more stuff, and so on." While Lightning compiler is different from the specific example Kirby gave (about the J language environment), I think it can be very useful tool in that kind of context. @Kirby: I'd be very curious to get your opinion of LC. Lightning Compiler (LC) is a wxPython based app. LC's purpose is to provide a friendlier environment to tests Python code snippets than the Python interpreter. It does include an interpreter (pyShell) but it is most likely to be used for its editor. You can execute the code that appears in the editing window and the output is redirected to an output window. raw_input() and input() are handled via dialogs. The basic layout (output window to the side or below the editor window) is customisable. Also, every command can be executed either by pressing a button or through a keyboard shortcut. You can also select part of the text (code) that appears on the editor window and execute it. If some text is selected, LC automatically uses it to be executed; otherwise it execute the entire window content. You can also ask LC to treat the code as a module and tests it with doctest by pressing a button (or keyboard shortcut). LC creates a module with the content of the editing window (or the selected part of it) and appends the lines: # import doctest doctest.testmod() # before running it. It can also use tests appearing in an external file, automatically adding the required commands, something like: # import doctest doctest.testmod() import unittest suite = doctest.DocFileSuite('some_file_queried_via_a_dialog') unittest.TextTestRunner("some verbosity level").run(suite) # You can "drag and drop" a python script into the editing window, instead of having to go through the open dialog. LC comes in a zip file with a sample app, showing how it can be embedded in other applications, as well as a sample script with doctests and a text file containing additional doctest based tests. For those that have tried LC before, a major change (in addition to the doctest feature) is the possibility to have more than one editing tab (as many as you want :-). Since LC uses wxPython, it can not be run with a basic Python installation. If there is some interest, I might try and adapt it so that it could use Tkinter instead as an option. This would probably be required if one wanted to use it with VPython for example. However, I have no experience with Tkinter. Any help would, of course, be appreciated :-) Thinking further about what Jeffrey suggested (having a collection of doctests online), I have been thinking about adding an option where one could fetch a code snippet (doctest) from a url. This would be fairly easy to implement. However, until there exists a significant collection of such code snippets, there is little need to consider adding this feature. As it is, one can always do a "cut-and-paste" from a browser to the editing window and work from there. Finally, as usual, I welcome any comments about this little app. Note that it is not intended as a complete IDE. André

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Re: [Edu-sig] Bootable Python CDs?
by David Boddie 28 Apr '06

28 Apr '06

On Thu Apr 27 17:47:15 CEST 2006, Ian Bicking wrote: > For something a bit more sophisticated, this is a good argument for > importing from URLs. Not inlined into the code, but if you added say > 'http://svn.classsite.com/repos/student-name' to sys.path, and an import > hook that knew how to read such sites (I think both importing from svn > and plain HTTP are possible, since you don't have to do a listdir to > attempt an import). HTTP isn't too hard. I wrote an import hook to do this a few years ago: http://www.boddie.org.uk/python/xhtmlhook/ Of course, it does other things besides import .py files over HTTP, but it shows that it can be done. These days it could be implemented more cleanly using the improved import hook mechanism. David

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Re: [Edu-sig] Bootable Python CDs?
by Laura Creighton 27 Apr '06

27 Apr '06

In a message of Wed, 26 Apr 2006 19:05:20 EDT, "Paul D. Fernhout" writes: >I previously wrote: >> Then you would have a custom Python which would be useful for wandering > >> faculty (assuming the admins let you reboot the machine, and it was >> configured to allowing booting from removable media). > >I just noticed this: > http://wiki.python.org/moin/PythonCd >"Welcome to your Python CD! This is a bootable CD based on [Debian >GNU/Linux and KNOPPIX. The special thing about it is that it has lots of >Python stuff!" > >Anyone used it? I didn't even know about it. Thanks. >I'm curious: is it even practical to expect to walk into most modern >educational computer lab in a typical school and expect to be able to >reboot all the computers to run from your own Python CD? Do people's >school computer labs typically allow a boot from removable media? Around here all student machines get completely wiped every month (sometimes every week) without fail. Otherwise they are packed with viruses, porn, and other junk. So bring-your-own distribution is the way to go. The only tricky thing is making sure that the students -- who want to save their own work on a CD -- actually do this properly. <snip> >--Paul Fernhout Laura

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Re: [Edu-sig] Bootable Python CDs?
by Radenski, Atanas 27 Apr '06

27 Apr '06

> -----Original Message----- > From: edu-sig-bounces(a)python.org [mailto:edu-sig-bounces@python.org] On > Behalf Of Douglas S. Blank > On Thu, 2006-04-27 at 10:47 -0500, Ian Bicking wrote: [snip] > I believe that Knoppix has the ability to gather up all of the files of > a student's desktop, and save them somewhere (network, flash memory, > floppy, etc). I think that is "Save KNOPPIX configuration" from the > "KNOPPIX" menu item. Then, the student can pick right back up from where > they left off. I host my Python courses with Moodle. Students can work on any system. At the end of their lab session, they use a browser to save a zipped folder with their intermediate results within Moodle. Later they can download that zipped folder anywhere and continue with the lab. (Moodle does not carry Python, so it should be installed on the system). No need to burn CDs or even use flash (although I would personally save a backup copy somewhere.) Atanas Atanas Radenski mailto:radenski@chapman.edu http://www.chapman.edu/~radenski/ If you think you are boring your audience, go slower not faster -- Gustav Mahler info/edu-sig

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Tips for wandering faculty
by kirby urner 27 Apr '06

27 Apr '06

By wandering faculty, I mean you're invited to gigs in a room you don't control and maybe have never seen before -- my situation rather often. A lab tech has likely installed Python ahead of time, but in a lab situation, there's always the question of rights, especially write rights. The typical thing is to not know or care about /site-packages, and so to have no writable access to *any* disk space on the default Python path. Your mileage may vary. We have several ways of addressing this situation, both from within the bash shell (if using Linux or maybe OS X) or from within Windows. To keep things Pythonic, I mix the subject of namespaces, essential early Python, with the example of sys, and sys.path in particular. Here's an importable resource you're able to append to, meaning whatever home directory you *can* write to is appendable to sys.path per this session. And that's a good thing. Plus it reinforces the core concept: import menagerie as zoo and/or from zoo import Dog, Monkey, Human. Many side bar topics also feature (including escape characters, if you want to stick with Windows backslash notation -- I have a take-it-or-leave-it attitude, as Python is quite willing to use forward slashes even on Windows). I like this segment for another reason: unlike some educators, I have no interest in "shielding" my students from the gross reality of some hunkering OS, complete with kernel, GUI resources and whathaveyou. Yes, a Linux system is huge and complicated. No, I don't favor "insulating" students from that hugeness, by constructing some dream world atop it and inside it, but unaware of it. This whole idea that we must "protect" students from this context is an anathema to me, as it's hypocritical. The people who *build* your pseudo or virtual reality need to know about these underlayers, these pipeworks and clockworks. Their not wanting to clue you in is a sign they're not treating you as a peer, but as a rat in some maze of their own devising. It may sound like I'm taking aim at Squeak here, but I'm not really. Squeak provides a more open source world that goes almost to the chip, just like Linux. You have access to the source code if you want it, down to where SmallTalk meets C, at which point there's not a lot to see (others have commented on this piece -- what Python might stand to gain from once the intended meetings happen in the Bay Area). More I'm taking aim at curricula which haven't discussed the file tree by the time we're dealing with 15 year olds. If you're already 15, and have no access to a bash shell, or the concepts of hard disk and filesystem, then IF you're actually using a hard drive with a file system, you're being ripped off, big time. Time to shop for a smarter set of teachers. Learn about partitions, standard trees and variants, search paths, config files. Don't let them hide that stuff behind a curtain. Kirby

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Re: [Edu-sig] Turtles all the way down (was Re: Tips ...)
by Laura Creighton 27 Apr '06

27 Apr '06

In a message of Wed, 26 Apr 2006 17:56:57 CDT, Ian Bicking writes: >Well, you could also just include Python without the OS ;) I think that >would be easier. Has anyone tried Movable Python >(http://www.voidspace.org.uk/python/movpy/)? It's only for Windows, but >I assume the technique is mostly portable (though some of the libraries >are not so easy, I imagine, like wxPython). Anyway, I'm sure you could >fit Python for several OS's onto one CD plus some useful libraries, and >save some time doing setup, which is otherwise a great way to waste a >lot of class time. Has anyone put together such a bundle? Or maybe >it's already out there, even if written for other reasons. > > >-- >Ian Bicking / ianb(a)colorstudy.com / http://blog.ianbicking.org I've used Knoppix http://www.knoppix.org to provide a bootable linux system packed with whatever it was I wanted to teach. So far it hasn't been python that I have been teaching, but I see no reason why this shouldn't work. Laura

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Re: [Edu-sig] Bootable Python CDs?
by Grégoire Dooms 27 Apr '06

27 Apr '06

Paul Fernhout wrote: > I previously wrote: >> > Then you would have a custom Python which would be useful for wandering >> > faculty (assuming the admins let you reboot the machine, and it was >> > configured to allowing booting from removable media). >> > > I just noticed this: > http://wiki.python.org/moin/PythonCd > "Welcome to your Python CD! This is a bootable CD based on [Debian > GNU/Linux and KNOPPIX. The special thing about it is that it has lots of > Python stuff!" > > Anyone used it? > I did not try that one but developped my own a few years ago: http://www.info.ucl.ac.be/~dooms/python/python.html It is a morphix mainmodule which is easily complemented by minimodules. I have been using it since to teach Python to adults. The CD includes VPython, Jython, mysql, Boost.Python, etc... I gets a little old now and would need a upgrade (Python 2.3, some newer network cards not supported). > I'm curious: is it even practical to expect to walk into most modern > educational computer lab in a typical school and expect to be able to > reboot all the computers to run from your own Python CD? Do people's > school computer labs typically allow a boot from removable media? > At the place where I use this CD, they disable USB but let me boot from the CD. Best, -- Grégoire Dooms.

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