Archive for January 26, 2015

Fourth edition of Python Media Computation released today: Teacher resources and desirable difficulties


According to Amazon, the Fourth Edition of the Python Media Computation book is released today (see page here). That’s the new cover above. I’ve been working on the 4th edition for most of the summer. Some of the bigger changes are:

  • Before we manipulate pictures, we manipulate letters, words, and language, e.g., build “MadLib” and “koan” generators, and encoding and decoding keyword ciphers. Language is a medium, too, and it’s easier to get started (for some folks) with the smaller-iteration loops of text before getting to the thousands-of-iterations loops of pixels in a picture. It’s an optional chapter — everything introduced there gets introduced again later.
  • Since the new version of JES fixed a round-off error in the Turtle class, we can do recursive turtle manipulations now (which tended to get messed up in earlier forms of JES).
  • I juggled content around so that we do more with conditionals and querying the pixel for its position, before we introduce nested loops. Nested loops are really hard for students, and I learned (from seeing the code that my students wrote) that they can do far more than I’d guessed with single loops — even with multiple pictures. I included more of that.
  • I have tried (for the last two editions) to provide screen-scraping examples, e.g., writing code to pull weather, news, or friends’ information from websites.  It’s getting harder and harder to write that kind of code.  Instead, I decided to provide more code that parses CSV files, as can be found at Open Data Journalism sites (like at The Guardian) and sources like the US Census.  The examples are still about parsing out useful information, but it’s a lot easier to parse CSV and encouraged at these sites.
  • There are more end of chapter problems, and new pictures.  And trying to catch all the errors in the Third Edition that master teachers like Susan Schwartz (at West Point) found.

We’re working on teacher resources now. Currently in development (aiming to have ready in the next couple months) the Powerpoint slides for each chapter of the book, a collection of all the code in the book for teachers, and a solutions manual for every end of chapter problem. These are surprisingly controversial. There are lots (mostly University) teachers who think that I shouldn’t provide any of these resources — teachers should be able to develop all of those themselves. Most of the high school and community college teachers I know appreciate having them.

In searching for the Fourth Edition on Amazon, I read the comments on the Third Edition (see here). Authors probably shouldn’t read the reviews of the book — they’re painful. But I did, and even worse, I actually responded.

Here is a quote from one, titled “False Advertising.”

Its biggest problem: false advertising. This is NOT a book on Python, it’s about JYTHON – A Java based imitation of Python.
Why? Well, there’s some pretty software, available to download, which uses the the JRE. The author chose to stick with this “easy learning environment” and basically cripple anyone wanting to write Python code for Blender, Maya, Android etc.

You may learn to program from this text, but don’t expect a trouble-free life when you get exposed to the real language.

Here was my response:

Everything in this book is useful when wanting to write Python code for Blender, Maya, Android, etc. This is an introductory book on data, loops, conditionals, and objects. Those parts of Python are identical in this book and in the Python that you’ll use in Blender, Maya, and Android. For introductory Python programming, Jython and CPython are exactly the same.

I was surprised to see the original commenter responded. His point was that some kinds of friction, in dealing with the “real world” is desirable:

As an introductory book, I would expect a section on how to install and configure Python. Written covering Windows, Linux, and the Mac OSX. There is no such section; the whole point of Jython is to “hide” this technical level. Which is fine for learning loops etc. but leaves a student lost when encountering Python out in the real world.

It’s an interesting perspective, kind of a “rugged individualism” approach. I do agree with the notion of desirable difficulties in learning (see more here),  but don’t agree that installing Python is one of those.  Do most Python programmers install Python themselves, or is it already installed on the servers, computers, etc. that they will be programming? Is it a critical part of learning a language? Is it significantly different than installing JES (try that here)? Are you “lost” and unable to program if you don’t install it yourself first?

A sad addendum to this story: Our Media Computation data structures book (see the Amazon page here) has gone out of print. The publisher didn’t notify us. Someone approached us about using the book, and was told that it was out of print. When I queried Pearson, they admitted it. More, because it’s not out of print everywhere (I guess it’s available in some non-US markets), Pearson won’t let us post the content anywhere. It’s a dead book now.

January 26, 2015 at 8:28 am 10 comments

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