Mailman 3 November 2018 - Edu-sig

a short essay about programming
by kirby urner 08 Dec '22

08 Dec '22

A common "error" (not too serious) that I see in beginning Python (and no doubt other languages, but Python is the one I'm teaching), is having a while condition that appears to put a lid on things, but then the flow all leaks away through break statements, such that the "front door" condition is never revisited. while guess != secret: guess = int(input("Guess?: ") if guess == secret: print("You guessed it!") break else: print("Nope, try again...") What's messed up about the above code is you never really go back to the top in the case where you'd get to leave. Rather, you exit by the back door, through break. So in that case, wouldn't have been simpler and more elegant, even more "correct" (dare I say it) to have gone: while True: # no ifs ands or buts guess = int(input("Guess?: ") if guess == secret: print("You guessed it!") break else: print("Nope, try again...") I see lots of heads nodding, and that could be the end of the matter, but then a next question arises: wouldn't this also be a more correct solution?: while guess != secret: guess = int(input("Guess?: ") if guess == secret: print("You guessed it!") continue # instead of break else: print("Nope, try again...") We're back to having a variable while condition, not a boolean constant, but this time we actually exit by means of it, thanks to continue or... while guess != secret: guess = int(input("Guess?: ") if guess == secret: print("You guessed it!") else: print("Nope, try again...") ... thanks to no continue. This last one is getting a thumbs up, but then I'd pause here and say "continue" can be easier on the eyes. It's unambiguous where it takes you, in contrast to having to scan on down the gauntlet, looking for possibly other open doors. "What happens next" should not require scanning ahead too far. Help us not to get lost. Be a civic-minded coder. I'm thinking of a programming style that advises two things: (a) if you use a while condition that's variable, that's expected to change, then your goal should be to always exit because of that, i.e. that should be your only exit point. Even if some other criterion suggests exiting, you have the option to flip that "lid" at the top, to crack that front door, and bounce the ball out. (b) which is why 'continue' is your friend. You are showing the user where your 'break' statements are, except you don't use "break" statements, as you've given a non-constant condition, and your aim is to make that your ONLY exit point. In short: never use break to exit a while loop unless your condition is while True. Instead, always flip the condition and exit through the font door. However, as soon as I make that rule I can think of good reasons to break it. The other programmers in the room are shaking their heads. Won't we lose information, needed elsewhere in the program, if we "artificially" force a True condition to False. Aren't we, in effect, lying? That concern could be addressed. Keep all the info true, just treat the "lid condition" (it "keeps a lid on it") as a flag. Go ahead and remember the user's guess. allowed = 5 tries = 1 exit = False while not exit: # no other way out guess = int(input("Guess?: ") if guess == secret: print("You guessed it!") exit = True # instead of break continue print("Nope, try again...") tries += 1 if tries == allowed: print("You've maxed out") exit = True continue I think we all understand the main issue: writing reader-friendly code, and rules for doing so. There's something comforting about approaching a while loop and knowing its not a leaky sieve, riddled with back doors, maybe even an exit( ) time bomb. But in the recursion world we want a minimum of two exits usually: when another round is called for versus when we've "hit bottom". Can we have it both ways? Conclusions: Lets not be too hasty with rules of thumb and: Lets keep the reader in mind when writing code. Just because the interpreter knows to compute the flow unambiguously, doesn't mean all ways of writing it are equally reader-friendly. What may seem a gratuitous gesture, an unnecessary flourish, may actually promote reader comprehension of your code, and that should be a goal as much as satisfying the interpreter. Kirby

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MineCraft with Python
by Jurgis Pralgauskis 03 Dec '22

03 Dec '22

Hi, intro: many kids like MineCraft :) probably you know/heared of MineCraft Pi https://www.raspberrypi.org/learning/getting-started-with-minecraft-pi/ But there seems to be Py for real MC http://coderdojotc.readthedocs.io/projects/python-minecraft/en/latest/ http://www.instructables.com/id/Python-coding-for-Minecraft/ PS.: a nice article (from js4MC world) https://github.com/walterhiggins/ScriptCraft/blob/master/docs/YoungPersonsG… -- Jurgis Pralgauskis tel: 8-616 77613; Don't worry, be happy and make things better ;) http://galvosukykla.lt

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[ANN] Josh Bartlett — pygame Artist in Residence
by René Dudfield 26 Nov '18

26 Nov '18

The pygame Artist in Residence grant *celebrates the Python arts community* and lends a tiny bit of support to someones art practice. An artist residency usually works something like; a person spends some time in either a gallery making something to present or in a music club doing a weekly spot. The pygame artist in residence will do it in their own space, but be present on the top of the pygame website in the form of a thumbnail and a link to their patreon/blog/artist statement/website/whatever. Josh Bartlett was the first recipient, and has been featured on the pygame website in October. Please see the pygame artist in residence profile page <https://www.pygame.org/artist-in-residence/1> for more info. Also, Josh is blogging <https://sqizit.bartletts.id.au/>, so you can read about him and some updates on his work there. ps. Thank you to everyone who applied, and those who helped with selection. Hopefully the next one will go more smoothly as the process is improved.

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Computer Science Teachers' Association of Ireland magazine
by Stephen Murphy 20 Nov '18

20 Nov '18

Hi all, Inspired by the post in about Python in France second level schools: A similar policy has been implemented in Ireland. Python must be used for our high school computer science specification. The Computer Science Teachers' Association of Ireland runs a monthly magazine where all things relevant to Computer Science for teachers is discussed. It would be very good if some Python enthusiasts on the list here would like to share their thoughts and opinions on Python in high schools through small article (1-3 pages) for the CSTAI magazine. The content would be completely up to yourself. If you would be interested, please let me know and I will send you some previous issues to see the style of writing. Best wishes, Stephen

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re Python in France etc. (Python and...?)
by kirby urner 20 Nov '18

20 Nov '18

I'm wondering if, when a curriculum embraces Python, this implies using Jupyter Notebooks? These two technologies seem so seamlessly connected in this day and age. I'm not suggesting Notebooks replace an IDE. But the idea of "coding" is changing given all the high level APIs out there. A pro in some field (other than software development) is likely to run only a few lines of code at a time. Google's TensorFlow tutorials take this approach. To say one is "learning Python" does not imply one is planning to write applications, not even websites. Python is a swap-in for MATLAB or R in many contexts. It's embedded. Here's me on the Teaching with Jupyter Notebooks discussion list (public archive) promoting the concept of embedding videos *about the very notebook they're embedded within*. Think of tutorials. I link to an example, viewed with nbviewer given Github skips showing the Youtubes in its native rendering engine. https://groups.google.com/d/msg/jupyter-education/3u1cvg1vza0/TYM1je1EAwAJ Kirby

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Python will be the official programming language for education in France
by Jacqueline Kazil 15 Nov '18

15 Nov '18

https://twitter.com/nnja/status/1062621193696612352

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"chopsticks" piano notes as ML feed in Intro Course (experimental)
by kirby urner 11 Nov '18

11 Nov '18

Here's another case where I might have stumbled on an andragogic technique another Python teacher is already well-known for using. Or not, we shall see. Old technique (for teaching properties): In an earlier chapter, I stumbled upon having @property decorate a circle so you could change radius, area or circumference with simple "setattr" dot notation e.g. c.area = 10, and the other two attributes would change automatically. [1] Thanks to how type property uses the Descriptor pattern, that's quite doable and is a clear demonstration of what properties allow, drawn from familiar grade school geometry. Turns out: Raymond Hettinger was sharing that little dharma already. Same karma! Great minds think alike (if I do say so myself). Aside: I've been meaning to do more with triangles and tetrahedrons, using @property... e.g. make AB longer and watch angles change. Sticking to right and/or equi-angular triangles keeps everything simpler. [2] The new technique (for introducing data structures and machine learning): So the new thing I might not be first to think of: lets use the "chopsticks pattern" from the musical score of Chopsticks (used universally in tutorials, almost a "hello, world" of Piano World) and call the chopstick note pairs "correct" amidst a myriad "not correct" bytes. Here's an octave: C D E F G A B C Chopsticks begins with F and G pressed. Then E and G. Then D and B. Then C and C. The first 22 seconds of this Youtube give the idea: https://youtu.be/waraNMP0kK8 So in "byte format": 0 0 0 1 1 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 1 0 1 0 0 0 0 0 0 1 are the "chopsticks" of interest. Then have Machine Learning algorithms tease out the pattern. Feed through 10,000 random strings of 1 and 0. [3] Mark the chopstick patterns "correct" (1) and the not-chopstick patterns "incorrect" (0), effectively forming a ninth column (the proverbial y in machine learning, where all the samples are X). This way, we get to play with (introduce) numpy.ndarrays and scikit-learn, but with more familiar thoughts about piano keys in the foreground, and a melody to boot. How good are these learning machines, once trained? Do they get random 10010100 right i.e. "not a chopstick"? Are they right every time? If intrigued and want more code, here's the link to the Jupyter Notebook in question: https://github.com/4dsolutions/SAISOFT/blob/master/OrderingData.ipynb (scroll to very end and come backwards would be my suggestion -- get the ML part first). I like how something so early in piano training feeds an intro to ML, given how piano and "player piano" relate to AI, of which ML is a part. Punch cards and all that. Very Westworld eh? https://youtu.be/elkHuRROPfk (not just Chopsticks anymore) I'm looking for "pathways through Python" that consist of a combination of "zoomed in" and "zoomed out" topics. Sometimes we look at nitty gritty, other times we need overview. Kirby [1] this older version (Oct 2016) doesn't have perimeter (circumference). Easy to add? (we do that as an exercise in class). https://github.com/4dsolutions/Python5/blob/master/Descriptors%20and%20Prop… [2] I've got this dynamite volume method, not invented by me, that just takes the six edge lengths for the arguments. https://github.com/4dsolutions/Python5/blob/master/tetravolume.py (used a lot in my stash) Lots more in the historical literature. E.g.: https://www.mathpages.com/home/kmath424/kmath424.htm More context: https://medium.com/@kirbyurner/uncommon-core-87a31b7f75b3 [3] My current function for doing that is maybe too long-winded as I concatenate strings. Why not just convert to binary from random 0-255. We could do that.

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Introducing RMOTR Notebooks: Free Jupyter Lab environment for students and educators
by Santiago Basulto 09 Nov '18

09 Nov '18

Hello folks. We're thrilled to finally be able to show something we've been working on lately: a free Jupyter Lab environment in the cloud, focused on education and publishing: https://notebooks.rmotr.com A little bit of background and motivation: we've been teaching Python and Data Science for a long time now, and helping our students get started is always problematic: setting up their environments involve installing Python, Jupyter, all the libraries, and adapt their environment based on their OS (WSL on Windows, bash on Macs, etc). That's why we just decided to create our own environment where students could just create a new project and start working without blockers. We've opted for Jupyter Lab since the beginning (it's still in "beta", but works great) which makes it a lot more intuitive. We're also helping our students manage their data, keeping it safe and backed up constantly, to avoid issues with Git or versioning. We're also focusing on the "publishing side": trying to give our students the possibility to showcase their work with minimum effort. Here's an example: https://notebooks.rmotr.com/santiagobasulto/cacophony-for-the-whole-family-… The service is completely free for educators and students, we want to keep democratizing the access to Python and these amazing environments. So you're all invited to try it out :) All your feedback and comments are appreciated. -- Santiago Basulto.- Co-founder @ rmotr.com

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