Mailman 3 August 2014 - 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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Re: [Edu-sig] Getting more involved with education and the PSF...
by Jeff Elkner 09 Jan '15

09 Jan '15

Two questions: 1. Andre, what do I need to do to begin maintaining that page? 2. Is there anyone in this thread not on edu-sig? My next reply will go only to the list. On Thu, May 22, 2014 at 10:09 AM, Jessica Nickel <jessanickel(a)gmail.com> wrote: > Sounds like a plan. I would be happy to talk with Selena about the work to > bridge the gap between k-12 educators and Python programmers. I was a k-12 > teacher for 10 years (music) and I have been working in schools with my > program to teach python coding to kids for the past year and a half, so I do > have some experience in that area. > > > > > On Thu, May 22, 2014 at 10:02 AM, Jeff Elkner <jeff(a)elkner.net> wrote: >> >> Great! So it seems we have two short term goals: >> >> 1. Get someone to agree to maintain the website (I'm volunteering if >> there isn't anyone else chomping at the bit to do it). >> 2. Reach out to Selena Deckelman to help her with her efforts to >> bridge the gap between developers and K-12 teachers (a noble goal >> indeed!). >> >> Do we agree that edu-sig is the sensible place to hold this conversation? >> >> If we do, can we ask Selena to join the list if she is not already >> there? I'll also encourage folks like Lee Harr (cc'd here), the >> creator of the wonderful Pynguin environment >> (https://code.google.com/p/pynguin/) to join the list and the >> discussion. >> >> On Thu, May 22, 2014 at 8:01 AM, Naomi Ceder <naomi.ceder(a)gmail.com> >> wrote: >> > One point of info I can add - the person you're thinking of running for >> > PSF >> > board is Selena Deckelman, who was on Nate's panel at the edu summit. >> > She's >> > been very into bridging the gap between developers and K-12 teachers. >> > >> > Naomi > >

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Re: [Edu-sig] https://www.python.org/success-stories/category/education/
by Laura Creighton 31 Aug '14

31 Aug '14

In a message of Sat, 30 Aug 2014 10:02:34 +0100, "Nicholas H.Tollervey" writes: >-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > >On 29/08/14 22:33, Jurgis Pralgauskis wrote: >> empty? >> >> -- Jurgis Pralgauskis tel: 8-616 77613; Don't worry, be happy and >> make things better ;) http://galvosukykla.lt >> >> >> _______________________________________________ Edu-sig mailing >> list Edu-sig(a)python.org >> https://mail.python.org/mailman/listinfo/edu-sig >> > >There's no obvious way that I know of to allow us to change this. I >presume there's a python.org web team somewhere who accept pull requests. > >I can think of many success stories (in the UK). Raspberry Pi, >Education Track at PyconUK, RaspberryJam, Raspberry Jamboree, London >Code Dojo, Reading Code Dojo etc etc etc > >N. Good luck. I think the only way to get changes now is to mail the private list psf-redesign(a)python.org. Don't bother mailing webmaster, that's me (and some others) and we cannot do anything, as we don't have the power to edit the site. We cannot read their private list, and they never mail anything to webmaster(a)python.org, so we don't know what (if anything) is doing on. My best informed (which admittedly is informed by the utter lack of information) guess is that nothing is going on. We've been forwarding such problems to psf-redesign for as long as the new site has been up, and figure we might as well have sent the lot to /dev/null. Laura

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Re: [Edu-sig] Looking back on OSCON XVI
by Laura Creighton 31 Aug '14

31 Aug '14

In a message of Sat, 30 Aug 2014 18:13:21 -0700, kirby urner writes: >On Sat, Aug 30, 2014 at 1:38 PM, Laura Creighton <lac(a)openend.se> wrote: > >> >In sketching out the Python ecosystem in broad brush terms, is it fair to >> >say NumPy gets a lot of US investment whereas PyPy is more an EU pet >> >project? Or is that too broad brush? >> >> Too broad. In investment terms, PyPy gets from _everywhere_, >> including lots from the USA. But PyPy core contributors are still >> mostly from not-in-the-USA ... unless things have changed in the last >> 6 months while I have been busy elsewhere. >> >> Laura >> >> >OK. I was partly asking because I know the US government is putting funds >directly into Blaze: > >http://continuum.io/blog/blaze > >I don't know if the US government itself directly pays for PyPy >development, but my impression is the EU itself does. > >Kirby The EU has in the past. But there hasn't been an EU grant proposal written for a while. Laura

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Python ecosystem (Blaze, NumPy, PyPy...)
by kirby urner 31 Aug '14

31 Aug '14

I should have changed the subject line. More on the funding story: http://news.dice.com/2013/02/06/continuum-analytics-using-darpa-funds-to-ex… EU funding for PyPy: http://conferences.agilealliance.org/sessions/20060356 Then there's trying to get funding to have NumPy support PyPy or vice versa: http://morepypy.blogspot.com/2011/10/numpy-funding-and-status-update.html Kirby On Sat, Aug 30, 2014 at 6:13 PM, kirby urner <kirby.urner(a)gmail.com> wrote: > On Sat, Aug 30, 2014 at 1:38 PM, Laura Creighton <lac(a)openend.se> wrote: > >> >In sketching out the Python ecosystem in broad brush terms, is it fair to >> >say NumPy gets a lot of US investment whereas PyPy is more an EU pet >> >project? Or is that too broad brush? >> >> Too broad. In investment terms, PyPy gets from _everywhere_, >> including lots from the USA. But PyPy core contributors are still >> mostly from not-in-the-USA ... unless things have changed in the last >> 6 months while I have been busy elsewhere. >> >> Laura >> >> > OK. I was partly asking because I know the US government is putting funds > directly into Blaze: > > http://continuum.io/blog/blaze > > I don't know if the US government itself directly pays for PyPy > development, but my impression is the EU itself does. > > Kirby > >

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Re: [Edu-sig] Looking back on OSCON XVI
by Laura Creighton 31 Aug '14

31 Aug '14

>In sketching out the Python ecosystem in broad brush terms, is it fair to >say NumPy gets a lot of US investment whereas PyPy is more an EU pet >project? Or is that too broad brush? Too broad. In investment terms, PyPy gets from _everywhere_, including lots from the USA. But PyPy core contributors are still mostly from not-in-the-USA ... unless things have changed in the last 6 months while I have been busy elsewhere. Laura

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Looking back on OSCON XVI
by Kirby Urner 30 Aug '14

30 Aug '14

In sketching out the Python ecosystem in broad brush terms, is it fair to say NumPy gets a lot of US investment whereas PyPy is more an EU pet project? Or is that too broad brush? I sat at the i18n table at OSCON and mostly met up with other North Americans, which can be plenty alien, and with Tatiana from Brazil. Tatiana's dad is a distinguished professor who believes in strong Portuguese literature, and Tati (as she's also known) became my ally when it came to advocating for Python courses in Brazilian Portuguese, and not necessarily translations exactly. Sure there's a place for Business English, but not as the only language of instruction. That was a "booth topic" (one of many) for O'Reilly School of Technology, with Matthew yakking in Russian, Japanese and Portuguese -- and English of course. He was our chief compliance officer during a recent chapter in which we sought to comply with specific rule books, now closed, and this was his first OSCON. In addition to Matthew, Kelly Hoover, Patrick Barton, myself, and Python course authors Steve Holden (Python) and Peter Scott (Perl), our school principal, Debra, manned the booth. Continuing with our i18n theme, two of my students, William and Natasha, both alumni and Russian-speaking, did student profiles with Debra (a standard video format). I haven't seen those yet, nor the three-way interview I joined in the camera booth, set up near to ours. Those video crews are kept busy with gig after gig and enjoyed getting a chance to let off steam at Horse Brass when it was all over. Holden had his OSCON Survivors Breakfast, top of the Hilton, where a couple of the program chairs got to unwind and hear a lot of sincerely positive feedback. Good OSCON this year. I'll close with links to my write-ups: http://worldgame.blogspot.com/2014/07/ramping-up.html http://worldgame.blogspot.com/2014/07/i18n.html http://worldgame.blogspot.com/2014/07/oscon-promo-keynote.html http://controlroom.blogspot.com/2014/07/oscon-2014-tutorials-day-1.html http://controlroom.blogspot.com/2014/07/scala-tutorial-at-oscon.html http://mybizmo.blogspot.com/2014/07/oscon-tutorials-day-2.html http://mybizmo.blogspot.com/2014/07/tutorial-on-nodejs-oscon-day-2.html http://mybizmo.blogspot.com/2014/07/more-keynotes-oscon-xvi.html http://controlroom.blogspot.com/2014/07/oscon-xvi.html http://worldgame.blogspot.com/2014/07/r0mls-talk-why-schools-dont-teach-ope… http://controlroom.blogspot.com/2014/07/oscon-xvi-wrap-up.html http://mybizmo.blogspot.com/2014/07/ramping-down.html DjangoCon starts here in town any day now, today in fact: http://www.djangocon.us/ Kirby PS: Pycon in Portland 2016, 2017 woo hoo!

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https://www.python.org/success-stories/category/education/
by Jurgis Pralgauskis 30 Aug '14

30 Aug '14

empty? -- Jurgis Pralgauskis tel: 8-616 77613; Don't worry, be happy and make things better ;) http://galvosukykla.lt

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