Mailman 3 October 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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*** Extended deadline *** CfP: 4th International Workshop on Model-driven Approaches for Simulation Engineering part of the Symposium on Theory of Modeling and Simulation (SCS SpringSim 2014)
by Daniele Gianni Oct. 27, 2013

Oct. 27, 2013

(Please accept our apologies if you receive multiple copies of this CFP) ################################################################# CALL FOR PAPERS 4th International Workshop on Model-driven Approaches for Simulation Engineering part of the Symposium on Theory of Modeling and Simulation (SCS SpringSim 2014) ################################################################# April 13-16, 2014, Tampa, FL (USA) http://www.sel.uniroma2.it/Mod4Sim14 ################################################################# # Papers Due: *** November 22, 2013 *** extended # Accepted papers will be published in the conference proceedings # and archived in the ACM Digital Library. ################################################################# The workshop aims to bring together experts in model-based, model-driven and software engineering with experts in simulation methods and simulation practitioners, with the objective to advance the state of the art in model-driven simulation engineering. Model-driven engineering approaches provide considerable advantages to software systems engineering activities through the provision of consistent and coherent models at different abstraction levels. As these models are in a machine readable form, model-driven engineering approaches can also support the exploitation of computing capabilities for model reuse, programming code generation, and model checking, for example. The definition of a simulation model, its software implementation and its execution platform form what is known as simulation engineering. As simulation systems are mainly based on software, these systems can similarly benefit from model-driven approaches to support automatic software generation, enhance software quality, and reduce costs, development effort and time-to-market. Similarly to systems and software engineering, simulation engineering can exploit the capabilities of model-driven approaches by increasing the abstraction level in simulation model specifications and by automating the derivation of simulator code. Further advantages can be gained by using modeling languages, such as UML and SysML – but not exclusively those. For example, modeling languages can be used for descriptive modeling (to describe the system to be simulated), for analytical modeling (to specify analytically the simulation of the same system), and for implementation modeling (to define the respective simulator). A partial list of topics of interest includes: * model-driven simulation engineering processes * requirements modeling for simulation * domain specific languages for modeling and simulation * model transformations for simulation model building * model transformations for simulation model implementation * model-driven engineering of distributed simulation systems * relationship between metamodeling standards (e.g., MOF, Ecore) and distributed simulation standards (e.g., HLA, DIS) * metamodels for simulation reuse and interoperability * model-driven technologies for different simulation paradigms (discrete event simulation, multi-agent simulation, sketch-based * simulation, etc.) * model-driven methods and tools for performance engineering of simulation systems * simulation tools for model-driven software performance engineering * model-driven technologies for simulation verification and validation * model-driven technologies for data collection and analysis * model-driven technologies for simulation visualization * Executable UML * Executable Architectures * SysML / Modelica integration * Simulation Model Portability and reuse * model-based systems verification and validation * simulation for model-based systems engineering To stimulate creativity, however, the workshop maintains a wider scope and welcomes contributions offering original perspectives on model-driven engineering of simulation systems. +++++++++++++++++++++++++++++++++++ On-Line Submissions and Publication +++++++++++++++++++++++++++++++++++ We invite paper submissions in three forms: 1. Full paper (max 8 pages), describing innovative research results. These papers are eligible for the best paper award and may be invited for an extended version in a special issue of the SCS SIMULATION journal. 2. Work-in-progress paper (max 6 pages), describing novel research ideas and promising work that have not yet been fully evaluated. 3. Short paper (max 6 pages), describing industrial and hands-on experience on any relevant area (i.e. military, government, space, etc.). All the papers must be submitted through the SCS conference management systems (http://www.softconf.com/scs/DEVS14/) and select the Mod4Sim track. The submissions must be in PDF format and conform to the SCS conference template (Word template is available at http://www.scs.org/upload/documents/templates/ConferenceSubmissionWORDTempl…, guidelines are available at http://www.scs.org/PDFs/formattingkit.pdf). All the submitted papers must be original and not submitted else where. Submitted papers will be peer reviewed with respect to their quality, originality and relevance. The authors of the accepted papers must register in advance for inclusion of their paper in the conference proceedings. Authors of accepted papers will be invited to update their papers basing on the reviews, before providing the camera ready. All accepted papers will be included in the conference proceedings and archived in both the ACM Digital Library and IEEE Digital Library. Authors may contact the organizers for expression of interest and content appropriateness at any time. +++++++++++++++ Important Dates +++++++++++++++ * Submission Deadline: November 22, 2013 (extended) * Decision to paper authors: January 5, 2014 * Camera ready due: February 2, 2014 * Conference dates: April 13-16, 2014 (to be confirmed within the SpringSim schedule) ++++++++++++++++++++ Organizing Committee ++++++++++++++++++++ * Daniele Gianni – University Guglielmo Marconi, Italy * Arnaud Cuccuru – CEA/LIST, France +++++++++++++++++ Program Committee +++++++++++++++++ * Steffen Becker - University of Paderborn, Germany * Paolo Bocciarelli - University of Rome TorVergata, Italy * David Chen - University of Bordeaux I, France * Andrea D'Ambrogio - University of Rome TorVergata, Italy * Cristian Englert - Serco, The Netherlands * Huascar Espinoza - ESI-Tecnalia, Spain * Paul A. Fishwick - University of Florida, USA * Sebastien Gerard - CEA/LIST, France * Carlos Juiz - University of Balearic Islands, Spain * Cristiano Leorato - RHEA, The Netherlands * Steve McKeever - Uppsala University, Sweden * Halit Oguztüzün - Middle East Technical University, Turkey * Chris Paredis - Georgia Institute of Technology, USA * Nicolas Rouquette - NASA/JPL, USA * Volker Schaus - DLR, Germany * Sara Tucci - CEA/LIST, France * Andreas Tolk - SimIS, USA * Anthony Walsh - European Space Agency, Germany * Heming Zhang - Tsinghua University, China *** Contact Information *** Daniele Gianni and Arnaud Cuccuru (workshop co-chairs) Emails: danielegmail-mod4sim(a)yahoo.it and arnaud.cuccuru(a)cea.fr

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New Textbook on Python with Data Structures
by Lambert, Kenneth Oct. 24, 2013

Oct. 24, 2013

I have just published a new textbook on Python programming with data structures. It will be released on November 6, 2013. Here is the main info: Title: Fundamentals of Python: Data Structures ISBN 13: 9781285752006 ISBN 10: 1285752007 Author: Kenneth A. Lambert Publisher: Cengage/PTR Pages: 496 Brief contents: 1. Basic Python Programming. 2. An Overview of Collections. 3. Searching, Sorting, and Complexity Analysis. 4. Arrays and Linked Structures. 5. Interfaces, Implementations, and Polymorphism. 6. Inheritance and Abstract Classes. 7. Stacks. 8. Queues. 9. Lists. 10. Trees. 11. Sets and Dictionaries. 12. Graphs. For more information, see http://www.cengageptr.com/Topics/TitleDetail/1285752007 or http://home.wlu.edu/~lambertk/python/index.html

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Re: [Edu-sig] Edu-sig Digest, Vol 123, Issue 3
by Alan O'Donohoe Oct. 21, 2013

Oct. 21, 2013

Last year I was invited to attend and lead the Education Track at PyCon, unfortunately I was unable to attend since I was not granted permission to be released from school. This year, it is more likely that I could attend, but I guess the moment may have passed? Alan O'Donohoe http://about.me/AlanODonohoe > On 21 Oct 2013, at 11:00, 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. Key PyCon Staff (Naomi Ceder) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 20 Oct 2013 20:15:31 -0500 > From: Naomi Ceder <naomi.ceder(a)gmail.com> > To: "edu-sig(a)python.org" <edu-sig(a)python.org> > Subject: [Edu-sig] Key PyCon Staff > Message-ID: > <CAKvj0qTbcF96ryq8=nqLnJHNz9O-286BLTBX4qbWJM5=7oo2=g(a)mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > Here are the key players for PyCon organizing for your reference: > > Diana Clark - PyCon Chair diana.joan.clark(a)gmail.com > Jesse Noller - Sponsorship jnoller(a)gmail.com > Brian Curtin - publicity brian(a)python.org > Ewa Jodlowska - event coordinator jodlowska2(a)gmail.com > > These should be the key people we have to talk to. If they don't know they > should be able to direct you to someone who does. > > And of course, the overall staff list is at > https://us.pycon.org/2014/about/staff/ > > But if you need to go to the organizers more generally, please just send it > through me, and I'll direct it to the right folks. > > Thanks, > Naomi > > -- > Naomi Ceder > https://plus.google.com/u/0/111396744045017339164/about >

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Key PyCon Staff
by Naomi Ceder Oct. 20, 2013

Oct. 20, 2013

Here are the key players for PyCon organizing for your reference: Diana Clark - PyCon Chair diana.joan.clark(a)gmail.com Jesse Noller - Sponsorship jnoller(a)gmail.com Brian Curtin - publicity brian(a)python.org Ewa Jodlowska - event coordinator jodlowska2(a)gmail.com These should be the key people we have to talk to. If they don't know they should be able to direct you to someone who does. And of course, the overall staff list is at https://us.pycon.org/2014/about/staff/ But if you need to go to the organizers more generally, please just send it through me, and I'll direct it to the right folks. Thanks, Naomi -- Naomi Ceder https://plus.google.com/u/0/111396744045017339164/about

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regarding 'iterables versus iterators' (example outbox, for peer review)
by Kirby Urner Oct. 10, 2013

Oct. 10, 2013

What is the difference between an iterator and an iterable? --- I will try to be concise: an iterator has a __next__ method for "inch worming" forward (from yield to yield internally, if defined by a generator function, but only some iterators are). Iterables, if they have an __iter__ method, should give rise to an iterator by that method. However, even something so dumb as a class with just __getitem__ can be treated as an iterable. Let's see: class Dumb: """uber primitive""" def __init__(self, it): self.thelist = it def __getitem__(self, n): return self.thelist[n] obj = Dumb(list("mary had a little lamb")) for d in obj: # iterables will work here print(d, end="") print() # can we use it with iter() ? theiter = iter(obj) if "__next__" in dir(theiter): print("wow, we have a grown up iterator!") for i in range(4): print(next(theiter)) Output: mary had a little lamb wow, we have a grown up iterator! m a r y === Kirby Urner Senior Python Mentor Python Track / OST

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PyconUK education track
by Nicholas H.Tollervey Oct. 3, 2013

Oct. 3, 2013

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Here's a write-up (one of many, but it's mine) about the PyconUK 2013 education track for teachers, students and developers that happened last weekend: http://ntoll.org/article/pyconuk2013-roundup It was a great success and a lot of fun was had by all..! Here's to more of the same next year. N. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Icedove - http://www.enigmail.net/ iQEcBAEBAgAGBQJSRzDYAAoJEP0qBPaYQbb6spIIALHmxdi840zCmYUqs1V4RAwx RbSwdxB9AeZpewgKX4KmquvK1I3/szsF0iRMrV5EPDBd4nPLmPlEGif+RpecMTZH iLnS95fWDYZE9h6uD9jus47662oZz0dUAoMrGsxh5WpuyA41uE+ngLvc/up3S9Id 8kmUaOjBamNIlsFooxIoLhSgqIWVS6DOn+Nv+/IpAQLo7UtSzVxnej3zHozqgMzI DpwYqxbFw0WGts3yrzBJkuQQSYLJj9hjEgh415ir+MUSwLRIMbb965GwEOr1MKBj ATInlgj6dt1GuDOMHqeCVIV706vOyze4U8mBhy7d+APzJnYPJ9T1JB3WhW/Zm3o= =J6pU -----END PGP SIGNATURE-----

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