Mailman 3 May 2013 - 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

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Re: [Edu-sig] RurPLE-NG is nice
by Jurgis Pralgauskis April 5, 2014

April 5, 2014

Some updates: - separated Variables Watch and Output panes, to be seen simultaneusly - implemented Breakpoints :) - beta style Todo: - let enter arbitrary watch expressions http://ftp.akl.lt/users/jurgis/python/rurple-NG053.png http://ftp.akl.lt/users/jurgis/python/rurple-ng-dz0-SplitLogVars_and_Breakp… for windows one doesn't need to install python separately, just unzip and run :) http://ftp.akl.lt/users/jurgis/python/RURPLE-NG-0.53%20%5bindependent%20exe… ps.: RurPLE-NG uses py3 unicode_literals, with_statement, division, print_function so code is generally py3 compliant. when wxpy will work well with py3 it shouldn't be too hard to port fully... >> >> just wanted to mention, >> that http://dev.lshift.net/paul/rurple/ >> is a very nice and lightweit PLE. >> >> what I like most (compared to RurPLE) are: >> 1) variables watch list (if it had breakpoints, it would rock :)

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Easy Web Environment to post pupils Python Creations
by Philip Bagge April 1, 2014

April 1, 2014

Dear Colleagues, My Y6 pupils (10-11 year olds) have been creating some simple text based linear adventures using Python. Does anyone know of a way we can play their adventures online? They are not very complicated. You can see the planning here. https://sites.google.com/site/pythoncodecouk/python-adventure Also as a new person to your forum does anyone know of an easy way to search you archives just in case someone has already answered this question. Thanks in advance for any help Phil Bagge -- Primary ICT Advanced Skills Teacher HCC Teacher & IT Manager http://code-it.co.uk

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Python MOOC (massive open online course)
by John Posner June 10, 2013

June 10, 2013

At the nytimes.com site, I came across a reference to this Python course in the comments to Thomas Friedman's latest column: http://blog.topfreeclasses.com/2012/12/an-introduction-to-interactive-pytho… Does anyone have any direct knowledge of this (or any other) Python MOOC? -John

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PyOhio Call for Proposals, Deadline of JUne 1st is fast approaching.
by Brian Costlow May 19, 2013

May 19, 2013

Hey all, What follows under here is our latest marketing pitch for the annual PyOhio conference. We're doing a free intro to programming class for 12-18 year-olds this year. If any of you are in the midwest, I have a couple of special requests. One, we'd really like to get a talk or two about using Python in education (as opposed to just educating people how to program in Python). Second, Katie Cunningham, who is teaching the class, could use some volunteers to help in the classroom that have teaching experience. Thanks! --Brian PyOhio 2013, the annual Python programming conference for Ohio and the surrounding region, will take place Saturday, July 27th, and Sunday, July 28th, 2013 at the Ohio Union, The Ohio State University in Columbus, Ohio. You can read more about the conference at http://pyohio.org. If you have questions about proposals, please email cfp(a)pyohio.org. You can also contact the PyOhio organizers at pyohio-organizers(a)python.org. PyOhio invites all interested people to submit proposals for scheduled talks, tutorials, and panels. All topics of interest to Python programmers will be considered. Standard presentation talk slots will be 40 minutes plus a 10 minute question-and-answer period. Tutorial slots will be 110 minutes long. The deadline to submit a proposal is June 1st. *Who Should Submit a Proposal? You. Your friends. Your friends' friends. Anyone with any level of Python knowledge is a candidate for a great topic at this conference. As we get attendees of all kinds, we need speakers of all kinds. In all ways and manners, we try to assemble the most diverse conference we can, and we do that with your help. Whether you got started with Python last month or you've been around for 20 years, we think you've got something to share. The Python community is stronger than ever and we're still reaching new areas, new industries, and new users. Be a part of growing Python by helping us change the future. In particular, we welcome submissions from people that have never done a talk before! And if you want help preparing a talk, let us know! Volunteers are eager to help new people do talks. You can submit more than one proposal. *What should I talk about? Anything to do with Python. Teach us about your favorite standard library module, or your favorite external library or framework. Show us something cool you built with Python. Science and data modeling. Web apps. Finance. Testing. Big data. DevOps. Integration with other languages. Do you want to work on a talk, but don't have any ideas? The topics below are up for grabs. Several people could easily work together on each one. Please take these ideas and stretch it out or focus on just one part of it or do whatever else you want. Parallelism shootout: threads vs multiple processes vs libevent. Walk through porting a library from python 2 to python 3 Python newbies. If you've programmed in another language first, Intro to Python for X Programmers, where X is Java, JS, C, PHP etc. If you're entirely new to programming, a short talk about your journey learning with Python would be great. We're still looking for someone to do an intro to Python tutorial for adults this year. Hint. *To Submit your proposal. Sign up for an account on the PyOhio website. Fill out a speaker profile. After that, you'll be able to submit a proposal. Pick talk or tutorial, and then describe your talk. You can edit stuff later, so don't over-think it. Regularly check your email for questions from the reviewers. *Keynote and Young Coder. We are thrilled to announce that Brandon Craig Rhodes will be this year's keynote speaker. Brandon has been a frequent speaker and contributor at PyCon, PyOhio, COhPy, and in his own words: "everywhere from the middle of Arkansas to the country of Poland." http://rhodesmill.org/brandon/ He is co-author of The Essentials of Python Network Programming, and author of a number of Python open source packages. https://bitbucket.org/brandon Also, Katie Cunningham will be giving an intro to Python class for young people 12-18 years old (7th-12th grade). This is a version of the Young Coder class she and Barbara Shaurette gave at PyCon this year. https://us.pycon.org/2013/events/letslearnpython/ *PyCamp PyCamp is a one-week, intensive, ultra-low-cost Python boot camp for beginners. It was developed by a Python user group and has been given to over 1000 students worldwide. Proceeds from PyCamps are used to sponsor Python community activities like PyOhio. PyCamp is taking place July 22-26 in the Ohio Union, the week before PyOhio weekend. Registration is open. http://trizpug.org/boot-camp/pyohio13/ *Register for PyOhio Registration for PyOhio is now open. PyOhio remains 100% free to attend. Just sign up for the free registration so we can get a head count. Or, if you want the T-Shirt, sign up for the paid ticket to get your shirt. (But don't do both!) http://pyohio.org/registration/ *Hotel(s) We have a discount room block at the Blackwell, right on OSU's campus for $120.00 a night. There are a few rooms blocked for the whole week for any out-of-towners going to PyCamp as well. Just tell them you are coming for PyOhio. http://www.theblackwell.com/ If it fills up, here are some other nearby hotels: http://www.hipmunk.com/hotels/Columbus-OH#!dates=Jul26,Jul28 Hope to see you all at the conference! The 2013 PyOhio Organizing Committee

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Re: [Edu-sig] Edu-sig Digest, Vol 118, Issue 1
by Jeff Elkner May 4, 2013

May 4, 2013

As a teacher who has been using Python as the intro programming language in my classroom since 1999, I just want to say "Pynguin rocks!" Thanks a 10**6, Lee, for creating it! Jeff Elkner Open Book Project http://openbookproject.net On Sat, May 4, 2013 at 6:00 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 > http://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. Re: [ANNC] pynguin-0.14 python turtle graphics application > (Jurgis Pralgauskis) > 2. Re: [ANNC] pynguin-0.14 python turtle graphics application > (Lee Harr) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 3 May 2013 19:01:17 +0300 > From: Jurgis Pralgauskis <jurgis.pralgauskis(a)gmail.com> > To: Lee Harr <missive(a)hotmail.com> > Cc: "edu-sig(a)python.org" <edu-sig(a)python.org>, > "python-list(a)python.org" <python-list(a)python.org> > Subject: Re: [Edu-sig] [ANNC] pynguin-0.14 python turtle graphics > application > Message-ID: > <CANDo6EyCdchu-0+CEAf-yUfBYA71U9p7RFSRC+qVCUoor=UJxQ(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi, > > do you plan to make step/debug functionality > as it is made in RurPLE? > > I generally like RurPLE-NG > http://dev.lshift.net/paul/rurple/ > > I improoved it fore easier learning > http://grokbase.com/t/python/edu-sig/129r2hkchm/rurple-ng-is-nice#20121113x… > > but moving around just rows and columns is a bit boring -- > Would it be hard to somehow merge code tracking with Pynguin? > > > > > On Sun, Apr 14, 2013 at 2:24 AM, Lee Harr <missive(a)hotmail.com> wrote: > >> Pynguin is a python-based turtle graphics application. >> It combines an editor, interactive interpreter, and >> graphics display area. >> >> It is meant to be an easy environment for introducing >> some programming concepts to beginning programmers. >> >> >> http://pynguin.googlecode.com/ >> >> >> This release adds several user-requested features, including >> circular arcs, SVG export, and undo. >> >> >> Pynguin is tested with Python 3.2.3 and PyQt 4.9.3 and >> will use Pygments syntax highlighting if available. >> >> Pynguin is released under GPLv3. >> >> >> Changes in pynguin-0.14: >> Important fixes >> >> Other fixes >> >> Pynguin API >> - Added font() to change font for use with write() >> - Added move parameter for write() >> - Added align and valign parameters for write() >> - Added arc() for circular arcs >> >> Canvas >> - Added SVG Export >> >> UI >> - Added ability to use translations >> - Added (basic) undo capability (ctrl-z) >> >> Integrated Editor >> - Added shortcut (ctrl-w) for removing doc pages >> - Stop asking for confirmation to remove empty doc page >> - Stop autosave from modifying empty doc page >> >> Integrated Console >> >> Examples >> - Added arc examples >> _______________________________________________ >> Edu-sig mailing list >> Edu-sig(a)python.org >> http://mail.python.org/mailman/listinfo/edu-sig >> > > > > -- > Jurgis Pralgauskis > tel: 8-616 77613; > Don't worry, be happy and make things better ;) > http://galvosukykla.lt >

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[ANNC] pynguin-0.14 python turtle graphics application
by Lee Harr May 3, 2013

May 3, 2013

Pynguin is a python-based turtle graphics application. It combines an editor, interactive interpreter, and graphics display area. It is meant to be an easy environment for introducing some programming concepts to beginning programmers. http://pynguin.googlecode.com/ This release adds several user-requested features, including circular arcs, SVG export, and undo. Pynguin is tested with Python 3.2.3 and PyQt 4.9.3 and will use Pygments syntax highlighting if available. Pynguin is released under GPLv3. Changes in pynguin-0.14: Important fixes Other fixes Pynguin API - Added font() to change font for use with write() - Added move parameter for write() - Added align and valign parameters for write() - Added arc() for circular arcs Canvas - Added SVG Export UI - Added ability to use translations - Added (basic) undo capability (ctrl-z) Integrated Editor - Added shortcut (ctrl-w) for removing doc pages - Stop asking for confirmation to remove empty doc page - Stop autosave from modifying empty doc page Integrated Console Examples - Added arc examples

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