TITLE: PyCon Day 2 AUTHOR: Eugene Wallingford DATE: April 23, 2023 12:09 PM DESC: ----- BODY: 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: 
    try:
        while X:
	    Y
	    raise _DONE
    except _DONE:
        None
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: 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. -----