May 26, 2023 12:37 PM

It's usually counterproductive to be doctrinaire

A short passage from Innocence, by Penelope Fitzgerald:

In 1927, when they moved me from Ustica to Milan, I was allowed to plant a few seeds of chicory, and when they came up I had to decide whether to follow Rousseau and leave them to grow by the light of nature, or whether to interfere in the name of knowledge and authority. What I wanted was a a decent head of chicory. It's useless to be doctrinaire in such circumstances.

Sometimes, you just want a good head of chicory -- or a working program. Don't let philosophical ruminations get in the way. There will be time for reflection and evaluation later.

A few years ago, I picked up Fitzgerald's short novel The Bookshop while browsing the stacks at the public library. I enjoyed it despite the fact that (or perhaps because) it ended in a way that didn't create a false sense of satisfaction. Since then I have had Fitzgerald on my list of authors to explore more. I've read the first fifty pages or so of Innocence and quite like it.

Posted by Eugene Wallingford | Permalink | Categories: General, Personal

May 19, 2023 2:57 PM

Help! Teaching Web Development in 2023

With the exception of teaching our database course during the COVID year, I have been teaching a stable pair of courses for the last many semesters: Programming Languages in the spring and our compilers course, Translation of Programming Languages, in the fall. That will change this fall due to some issues with enrollments and course demands. I'll be teaching a course in client-side web development.

The official number and title of the course are "CS 1100 Web Development: Client-Side Coding". The catalog description for the course was written years ago by committee:

Client-side web development adhering to current Web standards. Includes by-hand web page development involving basic HTML, CSS, data acquisition using forms, and JavaScript for data validation and simple web-based tools.

As you might guess from the 1000-level number, this is an introductory course suitable for even first-year students. Learning to use HTML, CSS, and Javascript effectively is the focal point. It was designed as a service course for non-majors, with the primary audience these days being students in our Interactive Digital Studies program. Students in that program learn some HTML and CSS in another course, but that course is not a prerequisite to ours. A few students will come in with a little HTML5+CSS3 experience, but not all.

So that's where I am. As I mentioned, this is one of my first courses to design from scratch in a long time. Other than Database Systems, we have to go back to Software Engineering in 2009. Starting from scratch is fun but can be daunting, especially in a course outside my core competency of hard-core computer science.

The really big change, though, was mentioned two paragraphs ago: non-majors. I don't think I've taught non-majors since teaching my university's capstone 21 years ago -- so long ago that this blog did not yet exist. I haven't taught a non-majors' programming course in even longer, 25 years or more, when I last taught BASIC. That is so long ago that their was no "Visual" in the language name!

So: new area, new content, new target audience. I have a lot of work to do this summer.

I could use some advice from those of you who do web development for a living, who know someone who does, or who are more up to date on the field than I.

Generally, what should a course with this title and catalog description be teaching to beginners in 2023?

Specifically, can you point me toward...

  • similar courses with material online that I could learn from?
  • resources for students to use as they learn: websites, videos, even books?

For example, a former student and now friend mentioned that the w3schools website includes a JavaScript tutorial which allows students to type and test code within the web browser. That might simplify practice greatly for non-CS students while they are learning other development tools.

I have so many questions to answer about tools in particular right now: Should we use an IDE or a simple text editor? Which one? Should we learn raw JavaScript or a simple framework? If a framework, which one?

This isn't a job-training course, but to the extent that's reasonable I would like for students to see a reasonable facsimile of what they might encounter out in industry.

Thinking back, I guess I'm glad now that I decided to play some around with JavaScript in 2022... At least I now have more context for evaluatins the options available for this course.

If you have any thoughts or suggestions, please do send them along. Sending email or replying on Mastodon or Twitter all work. I'll keep you posted on what I learn.

Posted by Eugene Wallingford | Permalink | Categories: Software Development, Teaching and Learning

May 07, 2023 8:36 AM

"The Society for the Diffusion of Useful Knowledge"

I just started reading Joshua Kendall's The Man Who Made Lists, a story about Peter Mark Roget. Long before compiling his namesake thesaurus, Roget was a medical doctor with a local practice. After a family tragedy, though, he returned to teaching and became a science writer:

In the 1820s and 1830s, Roget would publish three hundred thousand words in the Encyclopaedia Brittanica and also several lengthy review articles for the Society for the Diffusion of Useful Knowledge, the organization affiliated with the new University of London, which sought to enable the British working class to educate itself.

What a noble goal, enabling the working class to educate itself. And what a cool name: The Society for the Diffusion of Useful Knowledge!

For many years, my university has provided a series of talks for retirees, on topics from various departments on campus. This is a fine public service, though without the grand vision -- or the wonderful name -- of the Society for the Diffusion of Useful Knowledge. I suspect that most universities depend too much on tuition and lower costs these days to mount an ambitious effort to enable the working class to educate itself.

Mental illness ran in Roget's family. Kendall wonders if Roget's "lifelong desire to bring order to the world" -- through his lecturing, his writing, and ultimately his thesaurus, which attempted to classify every word and concept -- may have "insulated him from his turbulent emotions" and helped him stave off the depression that afflicted several of his family members.

Academics often live an obsessive connection with the disciplines they practice and study. Certainly that sort of focus can can be bad for a person when taken too far. (Is it possible for an obsession not to go too far?) For me, though, the focus of studying something deeply, organizing its parts, and trying to communicate it to others through my courses and writing has always felt like a gift. The activity has healing properties all its own.

In any case, the name "The Society for the Diffusion of Useful Knowledge" made me smile. Reading has the power to heal, too.

Posted by Eugene Wallingford | Permalink | Categories: General, Personal, Teaching and Learning

May 01, 2023 4:21 PM

Disconcerted by a Bank Transaction

I'm not sure what to think of the fact that my bank says it received my money NaN years ago:

screen capture from my bank's web site, showing that my transaction was received NaN years ago

At least NaN hasn't show up as my account balance yet! I suppose that if it were the result of an overflow, at least I'd know what it's like to be fabulously wealthy.

(For my non-technical readers, NaN stands for "Not a Number", and is used in computing interpreted as a value that is not defined or not representable. You may be able to imagine why seeing this in a bank transaction would be disconcerting to a programmer!)

Posted by Eugene Wallingford | Permalink | Categories: Computing, Personal

April 26, 2023 12:15 PM

Cultivating a Way of Seeing

Sometimes, I run across a sentence I wish I had written. Here are several paragraphs by Dan Bouk I would be proud to have written.

Museums offer a place to practice looking for and acknowledging beauty. This is, mostly, why I visit them.

As I wander from room to room, a pose diverts me, a glance attracts me, or a flash of color draws my eye. And then I look, and look, and look, and then move on.

Outside the museum, I find that this training sticks. I wander from subway car to platform, from park to city street, and a pose diverts me, a glance attracts me, or a flash of color draws my eye. People of no particular beauty reveal themselves to be beautiful. It feels as though I never left the museum, and now everything, all around me, is art.

This way of seeing persists, sometimes for days on end. It resonates with and reinforces my political commitment to the equal value of each of my neighbors. It vibrates with my belief in the divine spark, the image of God, that animates every person.

-- Dan Bouk, in On Walking to the Museum, Musing on Beauty and Safety

Posted by Eugene Wallingford | Permalink | Categories: General, Personal

April 24, 2023 2:54 PM

PyCon Day 3

The last day of a conference is often a wildcard. If it ends early enough, I can often drive or fly home afterward, which means that I can attend all of the conference activities. If not, I have to decide between departing the next day or cutting out early. When possible, I stay all day. Sometimes, as with StrangeLoop, I can stay all day, skip only the closing keynote, and drive home into the night.

With virtual PyCon, I decided fairly early on that I would not be able to attend most of the last day. This is Sunday, I have family visiting, and work looms on the horizon for Monday. An afternoon talk or two is all I will be able to manage.

Talk 1: A Pythonic Full-Text Search

The idea of this talk was to use common Python tools to implement full-text search of a corpus. It turns out that the talk focused on websites, and thus on tools common to Python web developers: PostgreSQL and Django. It also turns out that django.contrib.postgres provides lots of features for doing search out of the box. This talk showed how to use them.

This was an interesting talk, but not immediately useful to me. I don't work with Django, and I use SQLite more often then PostgreSQL for my personal work. There may be some support for search in django.contrib.sqlite, if it exists, but the speaker said that I'd likely have to implement most of the search functionality myself. Even so, I enjoyed seeing what was possible with modules already available.

Talk 2: Using Python to Help the Unhoused

I thought I was done for the conference, but I decided I could listen in one one more talk while making dinner. This non-technical session sounded interesting:

How a group of volunteers from around the globe use Python to help an NGO in Victoria, BC, Canada to help the unhoused. By building a tool to find social media activity on unhoused in the Capitol Region, the NGO can use a dashboard of results to know where to move their limited resources.

With my attention focused on the Sri Lankan dal with coconut-lime kale in my care, I didn't take detailed notes this time, but I did learn about the existence of Statistics Without Borders, which sounds like a cool public service group that needs to exist in 2023. Otherwise, the project involved scraping Twitter as a source of data about the needs of the homeless in Victoria, and using sentiment analysis to organize the data. Filtering the data to zero in on relevant data was their biggest challenge, as keyword filters passed through many false positives.

At this point, the developers have given their app to the NGO and are looking forward to receiving feedback, so that they can make any improvements that might be needed.

This is a nice project by folks giving back to their community, and a nice way to end the conference.


I was a PyCon first-timer, attending virtually. The conference talks were quite good. Thanks to everyone who organized the conference and created such a complete online experience. I didn't use all of the features available, but what I did use worked well, and the people were great. I ended up with links to several Python projects to try out, a few example scripts for PyScript and Mermaid that I cobbled together after the talks, and lots of syntactic abstractions to explore. Three days well spent.

Posted by Eugene Wallingford | Permalink | Categories: Computing, Software Development

April 23, 2023 12:09 PM

PyCon Day 2

Another way that attending a virtual conference is like the in-person experience: you can oversleep, or lose track of time. After a long morning of activity before the time-shifted start of Day 2, I took a nap before the 11:45 talk, and...

Talk 1: Python's Syntactic Sugar

Grrr. I missed the first two-thirds of this talk, which I greatly anticipated, but I slept longer than I planned. My body must have needed more than I was giving it.

I saw enough of the talk, though, to know I want to watch the video on YouTube when it shows up. This topic is one of my favorite topics in programming languages: What is the smallest set of features we need to implement the rest of the language? The speaker spent a couple of years implementing various Python features in terms of others, and arrived at a list of only ten that he could not translate away. The rest are sugar. I missed the list at the beginning of the talk, but I gathered a few of its members in the ten minutes I watched: while, raise, and try/except.

I love this kind of exercise: "How can you translate the statement if X: Y into one that uses only core features?" Here's one attempt the speaker gave:

        while X:
            raise _DONE
    except _DONE:

I was today days old when I learned that Python's bool subclasses int, that True == 1, and that False == 0. That bit of knowledge was worth interrupting my nap to catch the end of the talk. Even better, this talk was based on a series of blog posts. Video is okay, but I love to read and play with ideas in written form. This series vaults to the top of my reading list for the coming days.

Talk 2: Subclassing, Composition, Python, and You

Okay, so this guy doesn't like subclasses much. Fair enough, but... some of his concerns seem to be more about the way Python classes work (open borders with their super- and subclasses) than with the idea itself. He showed a lot of ways one can go wrong with arcane uses of Python subclassing, things I've never thought to do with a subclass in my many years doing OO programming. There are plenty of simpler uses of inheritance that are useful and understandable.

Still, I liked this talk, and the speaker. He was honest about his biases, and he clearly cares about programs and programmers. His excitement gave the talk energy. The second half of the talk included a few good design examples, using subclassing and composition together to achieve various ends. It also recommended the book Architecture Patterns with Python. I haven't read a new software patterns book in a while, so I'll give this one a look.

Toward the end, the speaker referenced the line "Software engineering is programming integrated over time." Apparently, this is a Google thing, but it was new to me. Clever. I'll think on it.

Talk 3: How We Are Making CPython Faster -- Past, Present and Future

I did not realize that, until Python 3.11, efforts to make the interpreter had been rather limited. The speaker mentioned one improvement made in 3.7 to optimize the typical method invocation, obj.meth(arg), and one in 3.8 that sped up global variable access by using a cache. There are others, but nothing systematic.

At this point, the talk became mutually recursive with the Friday talk "Inside CPython 3.11's New Specializing, Adaptive Interpreter". The speaker asked us to go watch that talk and return. If I were more ambitious, I'd add a link to that talk now, but I'll let you any of you are interested to visit yesterday's post and scroll down two paragraphs.

He then continued with improvements currently in the works, including:

  • efforts to optimize over larger regions, such as the different elements of a function call
  • use of partial evaluation when possible
  • specialization of code
  • efforts to speed up memory management and garbage collection

He also mentions possible improvements related to C extension code, but I didn't catch the substance of this one. The speaker offered the audience a pithy takeaway from his talk: Python is always getting faster. Do the planet a favor and upgrade to the latest version as soon as you can. That's a nice hook.

There was lots of good stuff here. Whenever I hear compiler talks like this, I almost immediately start thinking about how I might work some of the ideas into my compiler course. To do more with optimization, we would have to move faster through construction of a baseline compiler, skipping some or all of the classic material. That's a trade-off I've been reluctant to make, given the course's role in our curriculum as a compilers-for-everyone experience. I remain tempted, though, and open to a different treatment.

Talk 4: The Lost Art of Diagrams: Making Complex Ideas Easy to See with Python

Early on, this talk contained a line that programmers sometimes need to remember: Good documentation shows respect for users. Good diagrams, said the speaker, can improve users' lives. The talk was a nice general introduction to some of the design choices available to us as we create diagrams, including the use of color, shading, and shapes (Venn diagrams, concentric circles, etc.). It then discussed a few tools one can use to generate better diagrams. The one that appealed most to me was Mermaid.js, which uses a Markdown-like syntax that reminded me of GraphViz's Dot language. My students and use GraphViz, so picking up Mermaid might be a comfortable task.


My second day at virtual PyCon confirmed that attending was a good choice. I've seen enough language-specific material to get me thinking new thoughts about my courses, plus a few other topics to broaden the experience. A nice break from the semester's grind.

Posted by Eugene Wallingford | Permalink | Categories: Computing, Software Development, Teaching and Learning

April 22, 2023 6:38 PM

PyCon Day 1

One of great benefits of a virtual conference is accessibility. I can hop from Iowa to Salt Lake City with the press of a button. The competing cost to virtual conference is that I am accessible ... from elsewhere.

On the first day of PyCon, we had a transfer orientation session that required my presence in virtual Iowa from 10:00 AM-12:00 noon local time. That's 9:00-11:00 Mountain time, so I missed Ned Batchelder's keynote and the opening set of talks. The rest of the day, though, I was at the conference. Virtual giveth, and virtual taketh away.

Talk 1: Inside CPython 3.11's New Specializing, Adaptive Interpreter

As I said yesterday, I don't know Python -- tools, community, or implementation -- intimately. That means I have a lot to learn in any talk. In this one, Brandt Bucher discussed the adaptive interpreter that is part of Python 3.11, in particular how the compiler uses specialization to improve its performance based on run-time usage of the code.

Midway through the talk, he referred us to a talk on tomorrow's schedule. "You'll find that the two talks are not only complementary, they're also mutually recursive." I love the idea of mutually recursive talks! Maybe I should try this with two sessions in one of my courses. To make it fly, I will need to make some videos... I wonder how students would respond?

This online Python disassembler by popped up in the chat room. It looks like a neat tool I can use in my compiler course. (Full disclosure: I have been following Pamela on Twitter and Mastodon for a long time. Her posts are always interesting!)

Talk 2: Build Yourself a PyScript

PyScript is a Javascript module that enables you to embed Python in a web page, via WebAssembly. This talk described how PyScript works and showed some of the technical issues in writing web apps.

Some of this talk was over my head. I also do not have deep experience programming in the web. It looks like I will end up teaching a beginning web development course this fall (more later), so I'll definitely be learning more about HTML, CSS, and Javascript soon. That will prepare me to be more productive using tools like PyScript.

Talk 3: Kill All Mutants! (Intro to Mutation Testing)

Our test suites are often not strong enough to recognize changes in our code. The talk introduced mutation testing, which modifies code to test the suite. I didn't take a lot of notes on this one, but I did make a note to try mutation testing out, maybe in Racket.

Talk 4: Working with Time Zones: Everything You Wish You Didn't Need to Know

Dealing with time zones is one of those things that every software engineer seems to complain about. It's a thorny problem with both technical and social dimensions, which makes it really interesting for someone who loves software design to think about.

This talk opened with example after example of how time zones don't behave as straightforwardly as you might think, and then discussed Python's newest time zone library, pytz.

My main takeaways from this talk: pytz looks useful, and I'm glad I don't have to deal with time zones on a regular basis.

Talk 5: Pythonic Functional (iter)tools for your Data Challenges

This is, of course, a topic after my heart. Functional programming is a big part of my programming languages course, and I like being able to show students Python analogues to the Racket ideas they are learning. There was not much new FP content for me here, but I did learn some new Python functions from itertools that I can use in class -- and in my own code. I enjoyed the Advent of Code segment of the talk, in which the speaker applied Python to some of the 2021 challenges. I use an Advent of Code challenge or two each year in class, too. The early days of the month usually feature fun little problems that my students can understand quickly. They know how to solve them imperatively in Python, but we tackle them functionally in Racket.

Most of the FP ideas needed to solve them in Python are similar, so it was fun to see the speaker solve them using itertools. Toward the end, the solutions got heavy quickly, which must be how some of my students feel when we are solving these problems in class.


Between work in the morning and the conference afternoon and evening, this was a long day. I have a lot of new tools to explore.

Posted by Eugene Wallingford | Permalink | Categories: Computing, Software Development

April 21, 2023 3:33 PM

Headed to PyCon, Virtually

Last night, I posted on Mastodon:

Heading off to #PyConUS in the morning, virtually. I just took my first tour of Hubilo, the online platform. There's an awful lot going on, but you need a lot of moving parts to produce the varied experiences available in person. I'm glad that people have taken up the challenge.

Why PyCon? I'm not an expert in the language, or as into the language as I once was with Ruby. Long-time readers may recall that I blogged about attending JRubyConf back in 2012. Here is a link to my first post from that conference. You can scroll up from there to see several more posts from the conference.

However, I do write and read a lot of Python code, because our students learn it early and use it quite a bit. Besides, it's a fun language and has a large, welcoming community. Like many language-specific conferences, PyCon includes a decent number of talks about interpreters, compilers, and tools, which are a big part of my teaching portfolio these days. The conference offers a solid virtual experience, too, which makes it attractive to attend while the semester is still going on.

My goals for attending PyCon this year include:

  • learning some things that will help me improve my programming languages and compiler courses,
  • learning some things that make me a better Python programmer, and
  • simply enjoying computer science and programming for a few days, after a long and occasionally tedious year. The work doesn't go away while I am at a conference, but my mind gets to focus on something else -- something I enjoy!

More about today's talks tomorrow.

Posted by Eugene Wallingford | Permalink | Categories: Computing, Software Development

April 09, 2023 8:24 AM

It Was Just Revision

There are several revised approaches to "what's the deal with the ring?" presented in "The History of The Lord of the Rings", and, as you read through the drafts, the material just ... slowly gets better! Bit by bit, the familiar angles emerge. There seems not to have been any magic moment: no electric thought in the bathtub, circa 1931, that sent Tolkien rushing to find a pen.

It was just revision.


... if Tolkien can find his way to the One Ring in the middle of the fifth draft, so can I, and so can you.

-- Robin Sloan, How The Ring Got Good

Posted by Eugene Wallingford | Permalink | Categories: General, Software Development, Teaching and Learning