Mailman 3 June 2016 - Edu-sig

a short essay about programming
by kirby urner Dec. 8, 2022

Dec. 8, 2022

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

8 17

MineCraft with Python
by Jurgis Pralgauskis Dec. 4, 2022

Dec. 4, 2022

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

6 6

turtle coordinates: Y increase downards - as in most graphics API?
by Jurgis Pralgauskis July 2, 2018

July 2, 2018

Hi, usually in computer graphics Y is counted to increase downwards. I casn do it with: setworldcoordinates(0, 400, 600, 0) but then, "right(..)" turns to the left :/ I could swap: right, left = left, right but on errror I get a bit misleading message >>> right() Traceback (most recent call last): File "<pyshell#10>", line 1, in <module> right() TypeError: left() takes exactly 1 argument (0 given) I thought to make this hack for kids, so better clearer error msgs... Any Ideas? Thanks :) -- Jurgis Pralgauskis tel: 8-616 77613; Don't worry, be happy and make things better ;) http://galvosukykla.lt

6 20

more follow-up re Pycon / EduSummit
by kirby urner July 9, 2016

July 9, 2016

Quiet around here, because the action is all on Twitter I think. Anyway, more blogged followup. I still can't find a Micro:Bit for sale in this neck of the woods, like at Fry's (our electronics superstore) or SurplusGizmos. http://worldgame.blogspot.com/2016/06/more-edusummit-business.html What if a family from the UK enrolls junior in the International School (downtown) and wants junior to stay abreast her or his peers. The code school I haunt is just a couple blocks away, why not go there after school? Fry's does have the Pi though. I just learned the manufacturer was sold to a Swiss company (I tweeted about it). Kirby

4 13

Re: [Edu-sig] O'Reilly Webcast: Doing Math with Python (Amit Saha)
by Sergio Rojas July 2, 2016

July 2, 2016

---------------------------------------------------------------------- Message: 1 Date: Sun, 26 Jun 2016 19:38:27 +1000 From: Amit Saha <amitsaha.in(a)gmail.com> To: "edu-sig(a)python.org" <edu-sig(a)python.org> Subject: [Edu-sig] O'Reilly Webcast: Doing Math with Python Message-ID: <CANODV3kQ4vPgsN2HtCURiLueuLAUZbiT2Waq8vx4sWjapuGa9g(a)mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Hi all, I am very excited to share that I am doing a webcast this coming week with O'Reilly titled "Doing Math with Python" (http://www.oreilly.com/pub/e/3712[http://www.oreilly.com/pub/e/3712]). You can register for it on the event page. Here are the date and time of the webcast: Wed, June 29th at 7 PM, San Francisco Wed, June 29th at 10pm, New York Thu, Jun 30th at 3am - London Thu, Jun 30th at 7:30am - Mumbai Thu, Jun 30th at 10am - Beijing Thu, Jun 30th at 11am - Tokyo Thu, Jun 30th at 12pm - Sydney I have created a GitHub repository (https://github.com/doingmathwithpython/oreilly-webcast-2016[https://github.…) which will have the rough transcript, final slides and the code examples as Jupyter Notebooks. Hope you can join me there. Best Wishes, Amit. ------------------------------ Hi Amit, What is needed to successfully run your jupyter notebook "Interactive Mandelbrot Set.ipynb"? When opening, it shows the Mandelbrot picture at the bottom. When executing the cell, nothing shows up. I am using: Python 3.5.1 |Anaconda 4.0.0 (64-bit)| (default, Dec 7 2015, 11:16:01) [GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux which includes: IPython : 4.1.2 Numpy : 1.10.4 Matplotlib : 1.5.1 Scipy : 0.17.0 Regards, Sergio PD. the other notebooks execute fine

3 3

O'Reilly Webcast: Doing Math with Python
by Amit Saha June 26, 2016

June 26, 2016

Hi all, I am very excited to share that I am doing a webcast this coming week with O'Reilly titled "Doing Math with Python" (http://www.oreilly.com/pub/e/3712). You can register for it on the event page. Here are the date and time of the webcast: Wed, June 29th at 7 PM, San Francisco Wed, June 29th at 10pm, New York Thu, Jun 30th at 3am - London Thu, Jun 30th at 7:30am - Mumbai Thu, Jun 30th at 10am - Beijing Thu, Jun 30th at 11am - Tokyo Thu, Jun 30th at 12pm - Sydney I have created a GitHub repository (https://github.com/doingmathwithpython/oreilly-webcast-2016) which will have the rough transcript, final slides and the code examples as Jupyter Notebooks. Hope you can join me there. Best Wishes, Amit.

1 0

PD for math teachers (was digest)
by kirby urner June 6, 2016

June 6, 2016

<< SNIP >> It's going to be slow going, but with resources like Amit's book, my book, > and Kirby's future book, math teachers will no longer feel alone in wanting > to modernize their field. > > Peter Farrell > Thanks for reminding me of my future book. I just emailed you some draft text suggested how we might start on defining types, when we're ready. I agree we needn't start with that. Python's built-in types are enough to start with. Kirby

1 0

Re: [Edu-sig] Edu-sig Digest, Vol 155, Issue 3
by Peter Farrell June 6, 2016

June 6, 2016

Thanks for taking me around, Kirby! I'm pursuing PD opportunities here in the SF Bay Area, and I'd love to come back and co-teach a "Math Through Technology" class at <guild /> ! I agree wholeheartedly with the EdSurge article Amit forwarded. I recently gave a demo lesson at a school that doesn't yet have a CS program and I showed how the goals of programming linked to each of the "math strategies" the math teacher used to decorate the classroom: find patterns, plug in numbers, draw a graph, and so on. (But I didn't get the job.) It's going to be slow going, but with resources like Amit's book, my book, and Kirby's future book, math teachers will no longer feel alone in wanting to modernize their field. Peter Farrell On Mon, Jun 6, 2016 at 9:00 AM, <edu-sig-request(a)python.org> wrote: > Send Edu-sig mailing list submissions to > edu-sig(a)python.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://mail.python.org/mailman/listinfo/edu-sig > or, via email, send a message with subject or body 'help' to > edu-sig-request(a)python.org > > You can reach the person managing the list at > edu-sig-owner(a)python.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Edu-sig digest..." > > > Today's Topics: > > 1. How programming supports math, not the other way around > (Amit Saha) > 2. Re: How programming supports math, not the other way around > (kirby urner) > 3. Re: How programming supports math, not the other way around > (Amit Saha) > 4. Re: How programming supports math, not the other way around > (kirby urner) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 5 Jun 2016 06:19:19 +1000 > From: Amit Saha <amitsaha.in(a)gmail.com> > To: edu-sig(a)python.org > Subject: [Edu-sig] How programming supports math, not the other way > around > Message-ID: > <CANODV3=1fPsy-2TCbvG322Ma-g0RN35wsNOJH= > Z19RK6oqbPqg(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Interesting article: > > > https://www.edsurge.com/news/2016-05-31-how-programming-supports-math-class… >

1 0

Re: [Edu-sig] Edu-sig Digest, Vol 155, Issue 3
by Marianne McKenna June 6, 2016

June 6, 2016

I am currently out of the office. If you need help, please contact building tech support. If it's an immediate need, please contact Paul Musto or Patty Hunter. I will respond to your email as soon as I am able. Thanks

2 1

How programming supports math, not the other way around
by Amit Saha June 5, 2016

June 5, 2016

Interesting article: https://www.edsurge.com/news/2016-05-31-how-programming-supports-math-class…

2 3