Mailman 3 January 2015 - 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

Re: [Edu-sig] (no subject)
by Charles Cossé Jan. 25, 2015

Jan. 25, 2015

Hello André, On Sat, Jan 24, 2015 at 5:23 PM, Andre Roberge <andre.roberge(a)gmail.com> wrote: > Why are you spamming the edu-sig list: you were replying to an email that > was never sent to that list. > > If that's to have people noting never to recommend Asymptopia software and > autoteach.net, and actually tell people you consider them to be spammers, > you can say "mission accomplished" as far as I am concerned. > > André Roberge > > Sorry for the misunderstanding. I was, in fact, responding to the following message from Sebastian Silva: from:Sebastian Silva <sebastian(a)fuentelibre.org> to:Charles Cossé < ccosse(a)gmail.com> cc:"edu-sig(a)python.org" <edu-sig(a)python.org> date:Fri, Jan 23, 2015 at 11:57 AMsubject:Re: [Edu-sig] (no subject):Important mainly because of your interaction with messages in the conversation. But you appear to be correct because I don't see this message in the edu-sig archives, which is also why I had a 3x post last week, ie because they appeared to be not going through. Perhaps there is something wrong with the edu-sig mailman daemon? Anyway, I've read many of your posts over the years, and as a Python user, developer and serious advocate of 15 years I do believe I am in the right place to discuss a non-commercial, open source product with "Python" and "Education" written all over it. I'm no spammer and I've worked very hard for several years to make this project a reality. I hope that it can advance Python, Parents and Open Source Education Software, all. I'm sure there is a misunderstanding somewhere here, but it's hard to trace if messages are being deleted from the queue or whatever is going on. Let's see if this goes through ... Best Regards, Charles > On Sat, Jan 24, 2015 at 8:17 PM, Charles Cossé <ccosse(a)gmail.com> wrote: > >> Thanks for keeping this discussion alive, Sebastian. >> >> >There are plenty of "portal" and LMS and such web software around. What >> is the need for a new one? >> >> "You can lead a child to quality educational resources, but you can't >> make them care" -- *me* :) >> So, the credit-meter gets them to *care*. And not only *care*, but >> actually *ask* for more work ... math, science, geography, language, >> whatever ... they want internet access and it is suddenly in their interest >> to make an effort, regardless of material. I think that is the goal of any >> teacher, i.e. having students give a hoot about the material. >> >> Also, I think "caring" is a prerequisite to real learning and retention. >> In my experience this form of "caring", i.e. caring about earning credits, >> is enough. They don't have to love math, but after they are compelled to >> "care" in this way, they still come-away with the information and the >> skills. >> >> I think the following condensed overview is useful, and also *this new >> overview graphic >> <http://www.asymptopia.org/media/project_images/AutoTeachInfoGraphic.png>* >> : >> >>> This project is about teaching kids, first and foremost. It became >>> web-based so I could create and assign lessons from my office. The >>> credit-meter is what I was forced to resort to in order to get their >>> attention. Soon I recognized the system's potential for any subject, and so >>> made it possible for others to contribute. But how to get others to >>> contribute? Money! I would have paid for this. Other parents probably >>> would, too, but there would be trust issues on both sides, parents and >>> developers. And it could be messy ... unless you let parent break-down and >>> distribute their subscription fees to the developers of their choice. Trust >>> issues solved, clear for take-off, next stop synergy! >>> >> >> >In other words, how to handle "internet credit" and access control and >> portal provider, etc? >> >> Well, the good news is that these have all been solved and the solutions >> are up-and-running. Portal provider ... I've got it running on a cloud >> server in San Jose, California. Subscription payments are handled through >> PayPal. >> >> Here is the new user procedure: >> 1. Goto autoteach.net/subscribe and purchase a subscription. You can >> also buy the router pieces from me, and a pre-loaded SD card, or you can >> download the SD image from Github and buy the R-Pi & other pieces (antenna, >> power supply, case, SD) elsewhere. If you buy from me I will just send a >> box of parts, else if I assemble it would require FCC certification etc. >> So I'll send an instructions page along with. Anyway, the PayPal process >> redirects you back to autoteach.net, which auto-instantiates your parent >> account and sends you an email with your AccountID (=username, password). >> >> 2. You can immediately login and play around, but that's not required. >> >> 3. Assemble your R-Pi and boot-up the first time. >> >> 4. Navigate to 192.168.66.1 and you will see a Setup screen. >> >> 5. Enter the AccountID from the email and push "Setup". >> >> 6. Your R-Pi will pull your account info from autoteach.net, including >> all accounts you have setup there and your router configuration (default if >> you haven't logged into autoteach.net yet.) >> >> At this point, if you have never yet logged-in to autoteach.net, then >> you've just sync'd with your lone parent account. The Username and >> Password for both your parent account online, as well as your parent >> account on the router, are all just = AccountID. AutoTeach.net is >> whitelisted by default, on the router, and the firewall is open by default >> as well. >> >> You can configure everything on the router-side, but my colleague >> convinced me to spend 180 days implementing this web-sync capability, so >> now the recommended procedure is to do everything at autoteach.net and >> push the "sync" button on the router. It is much easier like this, indeed. >> >> By default you can create one more parent account and 2 kid accounts. >> >> Then, you the parent can login to autoteach.net from anywhere >> over-the-net and create assignments and assign to whichever kid(s) you want. >> >> Your kids connect via the AutoTeach R-Pi router (at home) and visit >> autoteach.net (because it's whitelisted) ... they each have their own 2 >> accounts, one on the router, one on the autoteach.net site. When they >> login to autoteach.net they see their list of assignments and perform >> whatever they want, as per the way you have configured for them (i.e. >> repeatable, do this first, etc). >> >> Once complete, then they login to 192.168.66.1 (AutoTeach R-Pi router at >> home) and push "Transfer Credit" ... which transfers the credits they've >> earned from the online site to their account on the router. Then they push >> "Connect" on their account interface at the router, and this causes the >> router to open-up the firewall to their list of WiFi devices (XBox, laptop, >> phone, etc) ... and they have full access for all devices until credits run >> dry .. then back to the "credit-feeder" website (i.e. autoteach.net) to >> take another assignment and earn more credits. >> >> Really I assure you that it's more complicated in writing than actually >> doing it. I am gearing-up to make a couple short videos demonstrating all >> of the above. >> >> This is turning into a short book ... so I'll AutoSilence myself ... in a >> moment ... :) ... but lastly, let me just add that my *Kickstarter >> <https://www.kickstarter.com/projects/2035655858/autoteach>* campaign is >> launched and there are 18 routers left. It's being sold at cost, possibly >> less than cost (!) .. in an effort to seed the parent community. >> >> Also important to mention are the benefits of being web-based: No setup, >> no dependencies, platform-independent, always current, use from anywhere, >> parents can compel kids from work/office/beach, centralization and >> strength-in-numbers (ie. developers) >> >> I also think the platform can serve as a "glue" between parent-users and >> plugin-developers, without which the two communities just drift separately. >> >> Finally (I PROMISE): As a developer your open source application can be >> made available outside of AutoTeach. There's no lock-in or anything like >> that. It's just an additional revenue stream for you. >> >> I hope that I HAVE NOT answered all your questions, such that you and >> others will continue to keep this conversation alive!! If you've made it >> reading this far then thank you! Hope to hear from more people on >> edu-sig. Don't be shy ... >> >> Charles Cossé >> Asymptopia Software <http://www.asymptopia.org> >> >> >> _______________________________________________ >> Edu-sig mailing list >> Edu-sig(a)python.org >> https://mail.python.org/mailman/listinfo/edu-sig >> >> >

2 2

Re: [Edu-sig] (no subject)
by Charles Cossé Jan. 25, 2015

Jan. 25, 2015

Thanks for keeping this discussion alive, Sebastian. >There are plenty of "portal" and LMS and such web software around. What is the need for a new one? "You can lead a child to quality educational resources, but you can't make them care" -- *me* :) So, the credit-meter gets them to *care*. And not only *care*, but actually *ask* for more work ... math, science, geography, language, whatever ... they want internet access and it is suddenly in their interest to make an effort, regardless of material. I think that is the goal of any teacher, i.e. having students give a hoot about the material. Also, I think "caring" is a prerequisite to real learning and retention. In my experience this form of "caring", i.e. caring about earning credits, is enough. They don't have to love math, but after they are compelled to "care" in this way, they still come-away with the information and the skills. I think the following condensed overview is useful, and also *this new overview graphic <http://www.asymptopia.org/media/project_images/AutoTeachInfoGraphic.png>*: > This project is about teaching kids, first and foremost. It became > web-based so I could create and assign lessons from my office. The > credit-meter is what I was forced to resort to in order to get their > attention. Soon I recognized the system's potential for any subject, and so > made it possible for others to contribute. But how to get others to > contribute? Money! I would have paid for this. Other parents probably > would, too, but there would be trust issues on both sides, parents and > developers. And it could be messy ... unless you let parent break-down and > distribute their subscription fees to the developers of their choice. Trust > issues solved, clear for take-off, next stop synergy! > >In other words, how to handle "internet credit" and access control and portal provider, etc? Well, the good news is that these have all been solved and the solutions are up-and-running. Portal provider ... I've got it running on a cloud server in San Jose, California. Subscription payments are handled through PayPal. Here is the new user procedure: 1. Goto autoteach.net/subscribe and purchase a subscription. You can also buy the router pieces from me, and a pre-loaded SD card, or you can download the SD image from Github and buy the R-Pi & other pieces (antenna, power supply, case, SD) elsewhere. If you buy from me I will just send a box of parts, else if I assemble it would require FCC certification etc. So I'll send an instructions page along with. Anyway, the PayPal process redirects you back to autoteach.net, which auto-instantiates your parent account and sends you an email with your AccountID (=username, password). 2. You can immediately login and play around, but that's not required. 3. Assemble your R-Pi and boot-up the first time. 4. Navigate to 192.168.66.1 and you will see a Setup screen. 5. Enter the AccountID from the email and push "Setup". 6. Your R-Pi will pull your account info from autoteach.net, including all accounts you have setup there and your router configuration (default if you haven't logged into autoteach.net yet.) At this point, if you have never yet logged-in to autoteach.net, then you've just sync'd with your lone parent account. The Username and Password for both your parent account online, as well as your parent account on the router, are all just = AccountID. AutoTeach.net is whitelisted by default, on the router, and the firewall is open by default as well. You can configure everything on the router-side, but my colleague convinced me to spend 180 days implementing this web-sync capability, so now the recommended procedure is to do everything at autoteach.net and push the "sync" button on the router. It is much easier like this, indeed. By default you can create one more parent account and 2 kid accounts. Then, you the parent can login to autoteach.net from anywhere over-the-net and create assignments and assign to whichever kid(s) you want. Your kids connect via the AutoTeach R-Pi router (at home) and visit autoteach.net (because it's whitelisted) ... they each have their own 2 accounts, one on the router, one on the autoteach.net site. When they login to autoteach.net they see their list of assignments and perform whatever they want, as per the way you have configured for them (i.e. repeatable, do this first, etc). Once complete, then they login to 192.168.66.1 (AutoTeach R-Pi router at home) and push "Transfer Credit" ... which transfers the credits they've earned from the online site to their account on the router. Then they push "Connect" on their account interface at the router, and this causes the router to open-up the firewall to their list of WiFi devices (XBox, laptop, phone, etc) ... and they have full access for all devices until credits run dry .. then back to the "credit-feeder" website (i.e. autoteach.net) to take another assignment and earn more credits. Really I assure you that it's more complicated in writing than actually doing it. I am gearing-up to make a couple short videos demonstrating all of the above. This is turning into a short book ... so I'll AutoSilence myself ... in a moment ... :) ... but lastly, let me just add that my *Kickstarter <https://www.kickstarter.com/projects/2035655858/autoteach>* campaign is launched and there are 18 routers left. It's being sold at cost, possibly less than cost (!) .. in an effort to seed the parent community. Also important to mention are the benefits of being web-based: No setup, no dependencies, platform-independent, always current, use from anywhere, parents can compel kids from work/office/beach, centralization and strength-in-numbers (ie. developers) I also think the platform can serve as a "glue" between parent-users and plugin-developers, without which the two communities just drift separately. Finally (I PROMISE): As a developer your open source application can be made available outside of AutoTeach. There's no lock-in or anything like that. It's just an additional revenue stream for you. I hope that I HAVE NOT answered all your questions, such that you and others will continue to keep this conversation alive!! If you've made it reading this far then thank you! Hope to hear from more people on edu-sig. Don't be shy ... Charles Cossé Asymptopia Software <http://www.asymptopia.org>

1 0

the lone star parameter
by kirby urner Jan. 22, 2015

Jan. 22, 2015

Not every Pythonista knows of the lone star. Say you want some keyword arguments that have to be mentioned, but you would never allow them to be reached positionally. Or: it's fine if you don't mention them, but if you know they exist, you have powers. def game_boot_up(pos0, pos1, *, cheat = False): # define a function Now you can start it with: >>> game_boot_up(1, 2) # ignore the keyword parameter (it has a default) and all will be fine. You can't try to probe with an extra positional "just in case": >>> game_boot_up(1, 2, True) # anything? -- raises exception But if you know the secret key by name... >>> game_boot_up(1, 2, cheat = True) Caveat: Python tends to blab what the "secret param" is in the Traceback so this isn't really how to embed a secret cheat. The point is to understand the role of the lone star better, a relatively obscure corner of the language. If the params after the lone star don't have default values then the corresponding keyword arguments will be required. Keyword are arguments required and yet are not pre-committed to any defaults. Useful. Kirby

1 0

"Easy Python learning paths" on reddit
by Andre Roberge Jan. 21, 2015

Jan. 21, 2015

Greetings, A few days ago, I created a new subreddit (http://www.reddit.com/r/pyproj/) whose description begins as follows: "This subreddit is a collection of small Python projects organized by theme and, within each project, increasing level of difficulty (whenever possible). The idea is to guide beginners, step by step, from writing a program requiring only a few lines of code to complete standalone applications." Right now, there is only one (almost complete) learning path, based on the "Guess the number" game (sometimes called "high and low"). Its description reads as follows: === Starting from a simple program where a user's single guess is compared with a randomly generated number, more complex versions are created to become either standalone GUI or web applications. The order in which the proposed versions appear below does not have to be strictly followed; for example, GUI based version can be done before doing a version that saves results to a file or a database. 1. Single guess for a randomly generated number 2. Guessing game: multiple attempts to guess a number 2.a Reverse guessing game: make the computer guess your number 2.b Computer vs Computer 3. Multiple games 4. Saving game results to a file 5. Saving game results to a database 6. Simple GUI adaptation 7. Full GUI implementation 8. Simple web version using Python's standard library 9. Simple web version using third party libraries (e.g. Flask, bottle) 10. Guess the number: computer vs computer using multiprocessing === There is also a "meta" learning path inviting learners to write unittests for either their own version of programs or for solutions written by someone else. If you have some ideas about similar "learning paths", or have ideas for enhancing the existing learning path, or simply want to provide a solution to a given "challenge", please do not hesitate to do so. Feel free to use any or all of the material posted (licensed CC0) with your students. André

1 0

Re: [Edu-sig] Edu-sig Digest, Vol 138, Issue 24
by Marianne McKenna Jan. 21, 2015

Jan. 21, 2015

I am away from the office. I will try to respond by email. If you need immediate help, please contact tech support. Thanks!

1 0

Re: [Edu-sig] Need resource for beginners
by Jurgis Pralgauskis Jan. 20, 2015

Jan. 20, 2015

Sounds nice! :) And what were the most difficult parts for participants (where they were getting stuck mostly): Python syntax, turtle commands, geometry, ...? On Sun, Jan 18, 2015 at 3:47 PM, Tamim Shahriar <tamim.shahriar(a)gmail.com> wrote: > So, the workshop went fine yesterday. Let me give you a brief on what we > did. > > There were 30 computers in the lab and total 43 participants. Couple of > students brought their own laptop. The participants were all girls and they > study in grade 9, 10 and 11. > > We started at 9:30 AM. The computers had Linux mint and as most of them > were not familiar with Linux, we helped them to get familiar with it > throughout the day. The felt like hackers in English movies, when they were > entering various commands in the terminal. > > First one and half hour, we spent with hour of code (from code.org). I > also showed them a clip of Frozen movie, to give them idea from where the > snowflakes thing came from. Later I found that most of them already watched > the movie. > > Then we went for a break and had snacks. After the break, we did another > hour of code. But this time, it was with Python. They created a chat bot. > As we had Internet in every computer, we used this : > https://groklearning.com/hoc-2014/. > > Then we had lunch break. When we returned from the break, we worked with > the snowflakes thing again, but this time, with Python. We used this > resource : http://www.raspberrypi.org/learning/snowflake-turtle/. Then > they built different geometric shapes with turtle package. > > At 5:30 PM we announced closing. Then Bristy Sikder a former IOI bronze > medalist of Bangladesh who studies at MIT now, talked to them. It was > inspiring. We also answered lots of questions the girls asked throughout > the day. Then we had evening snacks. > > At 7:00 PM the closing ceremony was held. The girls were looking so happy > and excited. We had some guests to inspire them. > > I thank Code it, girl! to give me the opportunity to conduct the workshop. > Tahmid Rafi, Ashiqur Rahman Mushfiq and Rashedul Hasan Shoikat were there > with me as trainers in the workshop. The food was awesome and thanks to > Hafiza Khatun Memorial Trust for sponsoring. > > I also thank the group members of this group. Your shared resources were > useful. > > I am attaching some photos. > > > Regards, > Tamim. > -- Jurgis Pralgauskis tel: 8-616 77613; Don't worry, be happy and make things better ;) http://galvosukykla.lt

2 1

Re: [Edu-sig] Edu-sig Digest, Vol 138, Issue 23
by Marianne McKenna Jan. 20, 2015

Jan. 20, 2015

I am away from the office. I will try to respond by email. If you need immediate help, please contact tech support. Thanks!

1 0

Re: [Edu-sig] real advice to a real student (comments welcome)
by Laura Creighton Jan. 17, 2015

Jan. 17, 2015

Can you suggest your student watch this video? http://www.thersa.org/events/rsaanimate/animate/rsa-animate-drive It is Dan Pink's _The Surprising Truth About what Motivates Us_ After he or she has done so, I have this added bit. Turns out, in test after test after test, what people want in order to be happy with what they do is Autonomy, Mastery and Purpose. (It's also what you need to give them if you want them to do that job well.) I would add, not on Dan Pink's list, that the opportunity to work with interesting and good people also is a factor. This means that when you go out and consider what do I need to do or learn in order to have a job in IT, it is important to work something out so that you will end up doing something that you find worthwhile. Otherwise, you will just quit and find something else to do ... People who are about to study something are at a bit of a disadvantage when it comes to making sure that they get autonomy, mastery and purpose. After all, by deciding to talk to Kirby you are demonstrating idependence and autonomy, and whenever you decide to learn something, like Python you are working on Mastery. The Purpose of 'I am going to transform myself into a Skilled Python programmer' handles the Purpose part rather well, and learning things on your own handles the autonomy part about as well as it can be done. With all these aspects being well handled, it is easy to fool yourself into thinking that all life as a Python programmer will work this way. But once you have done sufficient learning as to be able to get a job, it is quite possible to end up doing something that isn't autonomous (your boss rides you all the time about the work that needs doing), isn't challenging (we aren't paying you to learn around here, just to do things that you already know how to do) and thus doesn't increase your sense of mastery, and is fairly pointless (if I weren't getting paid to do this, I would never do anything like this at all). As Dan Pink mentions, the thing to do about money is to pay people well enough that it no longer becomes a motivating issue, because people who are paid far too little are always thinking about money and not about the job. Now, if you are in the position of being dependent on your parents for any money you receive, you may be deep in the land of 'not getting paid enough for your effort' because you are not getting paid at all. And, indeed, your life will be greatly improved once you start earning a decent wage .... But at this point the other factors start becoming the most important ones, and if you haven't understood this, you can end up in a pointless (but decently paying) job that doesn't allow you to grow, controls you and stresses you out. By understanding the problem you can make sure you do not end up there. Best of luck in life, whatever you choose to do -- Laura Creighton

3 2

(no subject)
by Charles Cossé Jan. 17, 2015

Jan. 17, 2015

Dear Edu-Sig Folks, Below is a link to a short pdf (840 words) describing a project that makes kids study and learn in exchange for internet access. The software behind the project uses Python in several places, as well as a Raspberry Pi and JavaScript. With these ingredients I have managed to cause non-math-loving children to beg for math, and much more. I would like to generate some discussion here on the edu-sig with anyone interested. I hope there are some! Thanks in advance for any and all feedback, Charles Cossé, Ph.D. Asymptopia Software http://www.asymptopia.org/media/project_files/AutoTeachBriefOverview.pdf

1 1