Mailman 3 December 2004 - Edu-sig

re: Pygeo, platforms, wx and Tk
by Arthur 19 Dec '04

19 Dec '04

I had written - >Bottom line problem is that I am using threading without understanding >threads. I'm guessing my answer is somewhere in getting down a level into >the threads themselves, rather than trying to get away with only dealing at >the level of the objects being threaded. >And now that I have a real problem to solve, I'll probably get down there >(eventually) and solve it Was able to spend some time on this today. Explored what I could find about threading and Tk, and learned (I think) - among other things - that the problem I was running into seems to (somewhat ironically) be the result of tcl implementing threading in 8.4 (and that the reason it was not cropping up on Windows is not a os issue, I'm thinking, but that tcl/tk is compiled on Windows without threading support) Whether the above is right or wrong ... I seem to have found a simple solution without going deeper in an implementation of threads, and qeues, and locks and semaphores and such. I start the TK thread from the VPython GTK Display class, sending "self" as a parameter to the Tk ControlPanel class. No problem here, as long as I don't try to start the TK mainloop from here. The Tk ContolPanel now has a reference to the Display and can send messages through that reference. The mainloop() call is from within __init__ of the Tk Control Panel. I had gotten that far before. Turns out, to get my bi-directional communication, all I need to do is setattr(Display,"control_panel",self) in the __init__ of the Tk ControlPanel class, so that now Display has a reference to the ControlPanel by which it can send messages of its events back in that direction. My first ever use of setattr. Knew it was there for something ;) Tidy and simple, I think. And I *do* have fun with Python. Art

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Re: [Edu-sig] Firefox ad
by Laura Creighton 18 Dec '04

18 Dec '04

In a message of Sat, 18 Dec 2004 14:20:26 PST, "Kirby Urner" writes: > >That's very cool Tim. I congratulate your dad for thinking of such a gre >at >gift. > >I need to find hardcopy of NYT 12/17. Maybe Coffee People still has some >. > >Kirby > >> You know the Firefox ad in the New York Times on the 17th? My dad bough >t >> me a spot (actually 2 spots) in that (I didn't even know til the day of >> the ad)! Look at my blog and/or the paper to see it; it's Tim Bauman an >d >> Kimaster George (no space; it's sort of spelled wrong). >> >> Tim >> Sorry,sorry, hit send too soon. God only knows what went out. Tim: not only do I not live in NYC, but not in the USA either. I live in Göteborg, Sweden. So can you please explain what you are so happy about? Laura

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Re: [Edu-sig] Firefox ad
by Laura Creighton 18 Dec '04

18 Dec '04

In a message of Sat, 18 Dec 2004 14:20:26 PST, "Kirby Urner" writes: > >That's very cool Tim. I congratulate your dad for thinking of such a gre >at >gift. > >I need to find hardcopy of NYT 12/17. Maybe Coffee People still has some >. > >Kirby > >> You know the Firefox ad in the New York Times on the 17th? My dad bought >> me a spot (actually 2 spots) in that (I didn't even know til the day of >> the ad)! Look at my blog and/or the paper to see it; it's Tim Bauman an >d >> Kimaster George (no space; it's sort of spelled wrong). >> >> Tim >> Ah, I live in Sweden, and I have no clue about what 'the Firefox ad in the New York Times on the 17th?' means.

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The power of interactivity
by Prasan Samtani 17 Dec '04

17 Dec '04

> I should introduce you to some of the characters on board edu-sig. > ........ Fascinating stuff, Kirby. Thanks! Just kicking around some more ideas on Python in education. I am the assistant for a class on Game Programming, and just got the Python bug when I started using it for a research project (which hopefully shows up in PyCon - http://www.tacticallanguage.com). Anyways, I've been thinking of ways to introduce Python as a model for scripting languages (OK, OK, I know Python is not a scripting language, but it is most often used as one in the video game development cycle) for this one semester course. A problem arises in splitting the limited course time between teaching them 'hard skills' such as building the bare metal of their 'Game Engine', and soft skills such as designing a scripting system. I'd also like the students to write the binding code themselves, not because I'm a masochist, but because it will be invaluable should they enter the industry and be in charge of writing a scripting system. My objectives for introducing Python will be to introduce an appreciation for language design (our school sticks to C++ for most of the undergraduate coursework), and to get them thinking about building flexible applications. The one option here is to write the basic framework myself, including some binding code (that'd give them a head start, but they'll have to extend the application on both the C++ and Python side - and that should give them the experience they need). Has anyone here experimented with using the C++/Python combination as an example of how one could produce flexible systems (not just for games, but in general). If so, I'd love to hear about it. Thanks, Prasan

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TinyP2P
by Dean Lake 17 Dec '04

17 Dec '04

Just saw this last night. TinyP2P - The World's Smallest P2P Application http://www.freedom-to-tinker.com/tinyp2p.html 15 lines of Python code. Written to "to illustrate the difficulty of regulating peer-to-peer applications." So, remember kids, wear your white hat when programming. =];-{i Dean

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Re: [Edu-sig] TinyP2P
by ajsiegel＠optonline.net 16 Dec '04

16 Dec '04

> Just saw this last night. > > TinyP2P - The World's Smallest P2P Application > http://www.freedom-to-tinker.com/tinyp2p.html > > 15 lines of Python code. > Written to "to illustrate the difficulty of regulating peer-to- > peer > applications." So that's what go get if you use tabs, not spaces. ;) Art

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Re: [Edu-sig] Hello, I'm Tim...
by The Bauman Family 16 Dec '04

16 Dec '04

> My son thought the video hysterical. I thought it interesting. I wonder > what you think of it. > > Yeah I guess it's interesting; not funny. It maily is talking about some newsgroup thing, when HTTP and websites ended up being the big thing (but this news show was before Netscape, wasn't it?).They say the advantage is that "there's a table marked football", and today those advantages are mostly gone. Most people use email or IM to communicate, which isn't like that. Also there are forums or mailing lists like this, but the average internet user doesn't use it communicate; they use it for Google or Amazon.com. > You may need Windows to view it. I hope you can scratch up a partition > somewhere where you might be running that particular operating system > ;) . > > Yeah I had to switch to Windows. Sound on Linux doesn't work, because the version of Alsa that Mandrake 10.0 came with doesn't have support for my sound card and there's no RPM for a newer version and compiling it didn't work. If I took the time to upgrade, I would get a new version. Also Totem Media Player, which Mandrake uses by default, doesn't work with WMVs very well (it tryed downloading a plugin, but nothing happened) for some reason. Tim. -- Visit my website: (and please be a supporter of free trade, free software, phr33 s0ftware, free dom, and free propoganda by giving others the url) http://kmg.is-a-geek.org Garunteed to be down at least 5% of the time.

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Re: [Edu-sig] Re: Pygeo, platforms, wx and Tk
by ajsiegel＠optonline.net 16 Dec '04

16 Dec '04

Scott writes - > Arthur wrote: > > Like most of us, I'm sure, almost anything I understand about > programming I > > understand because I needed to understand it to solve a real > problem. > > This is actually a learning style question. I am personally only > happyworking on a system when I "understand" the layer below it. I don't think I'm different really. Only more adjusted and resigned to working unhappily - having gotten started late in all of this. As a matter of fac, I'm not fully happy working in Python, not understanding C. Which is why PyPy excites me. Art

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re: Pygeo, platforms, wx and Tk
by Arthur 16 Dec '04

16 Dec '04

>And I *do* face a crucial functional issue with TK, and only on Linux, as >it happens, regarding threading. >I may try to present the issue later, to try to get some feedback, and >help determine whether the issue is inherent, a limitation of the >developer, or a limitation of the particular toolkit. Here goes: So I have 2 windows - one is a Display for the VPython rendering and is actually constructed as a class derived from the VPython display object (native on Windows, GTK1 on linux) The other is a TK control panel. The user can interact with either - pick and move points, for example, in the Display, or reveal or hide construction levels from the control Panel. So each must be in a loop, and the 2 windows need to be able to communicate with to each other as to any user action. On Windows, in the Display class I create the Panel, sending the Display as one of the arguments, while saving a reference to the Panel as an attribute of the Display class. And start a thread that sets off the TK loop for the Panel. The Display now has a reference to the Panel set on its creation, and the Panel now has a reference to the Display, sent to it as an argument. And the communication is bi-directional, via these references. Same tact on Linux produces an error something to the effect: "Attempt to start TK instance from a separate appartment" (definitely spelled with 2 p's). A search on this error message on python-list brings me to a post by Aahz, resident threading expert, asking why one would want to multi-thread a TK application. Implying, I think, that one can't. I am not sure that I need to. Or mean to. But nonetheless I can't find an approach here that yields bi-directional messaging other than the one that works on Windows. This is sounding both esoteric, and not well described. But I am not so much expecting as answer, as much as anyone's gut as to whether this is answerable, and whether my problem is in any way TK specific. Thanks. Art

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Help Testing IDLD patch
by John Zelle 16 Dec '04

16 Dec '04

Hello all, A while back, I responded to a post about some IDLE annoyances and said I was more concerned about IDLE 1.04's instablility under Windows. I have a very simple test that causes IDLE to hang, and it does not appear to be fixed in IDLE 1.1. A number of folks who are trying to use Python in education have reported frsutration with the situation. So..., I did some poking around myself. I do not have a very good understanding of the IDLE code, but I think I have found a simple fix for the error I can reproduce reliably. I would appreciate it if some of you who have noticed these problems with IDLE would give my patch a try and let me know if it helps out at all. I have added a single line to the PyShell.py file that lives in Python2.3/lib/idlelib. You can get my modified version here: http://mcsp.wartburg/edu/zelle/Python/PyShell.py. You should be able to use this as a drop-in replacement. Alternatively, you can search in it for my initials (JMZ) to find the line I added and just edit your own copy. Basically, the patch just does the equivalent of a keyboard-interrupt (ctrl-c) before closing the shell window. Any feedback on this would be greatly appreciated. A number of schools are wondering what they should use for Winter term. It would be a real shame if this flaw in IDLE causes Python to lose ground. --John ps. With this "fix", killing the IDLE shell window will produce a little "chatter" before it goes away. I can live with that.

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