Python Exceptions: Bonus Content

This post is a followup to my article The Basics of Exceptions in Python, but should make sense on its own as long as you are familiar with raise and try/except.

Let’s cover a few more advanced aspects of the Python exception system. We’ll move a bit faster and talk at a higher level than we did in the last post.

Topics we’ll hit:

The Basics of Exceptions in Python

This post was originally meant to be a small part of my discussion of the Go programming language (coming soon) as a way of drawing contrast between Python and Go, but turned out to be extensive enough to justify its own post.

Python’s model of exceptions is quite similar to that of other popular object-oriented languages like Ruby, JavaScript, and Java1. Errors flow differently than regular data; if not “handled”, they rise up through the entire function stack and crash the program. Developers are encouraged to write code to anticipate those exceptions, handle them before everything explodes, and change the logic flow of the program accordingly.

What exactly needs to be done in that “handling” step typically depends on what went wrong, and so there are many types of errors. Programmers can check the type of an error to determine what went wrong and react accordingly. Errors can be thought of as objects and their types as classes that can be subclassed like any other class. But unlike other data, they follow an error-specific path through the code, short-circuitiing functions all the way up the stack until handled.

Gym Etiquette 101

When I first started going to the gym, I was self-conscious every second. There’s a particular code of unwritten rules in the weightroom. Having a mentor really helps, and without one, it’s easy to be so uncomfortable that you don’t want to come back.

Over the years I’d like to think I’ve picked up most of the “rules”. Here’s a list I wish someone had given me when I was starting.

Careers in Programming

I recently visited Westville Correctional Facility, an Indiana penitentiary, to talk about jobs in the field of computing. It was an unusual opportunity that was honestly somewhat eye-opening; never have I had so enthusiastic and engaged an audience. I was sponsored through the Moreau College Initiative, a program in which residents of the facility are able to take full academic courses and potentially earn a bachelors degree before re-entering society. You can read more about the program here, if you are so interested.

Too Good To Be True?

The Too Good To Go app has been my fixation this summer. Since moving to a new neighborhood two months ago, I’ve picked up 43 surprise bags (all the more absurd because I didn’t discover the app until two weeks after moving). Dramatically increasing my consumption of sandwiches and pastries wasn’t in my original goals for the summer, but here we are. Too Good To Go lists “bags” that restaurants will sell you at a steep discount, though their contents will be a surprise.

Crafting Interpreters

In January, during some time off between jobs, I started working through Crafting Interpreters by Robert Nystrom. I think I originally discovered the book via r/ProgrammingLanguages. There aren’t that many accessible books for programming language design and implementation, so discovering the book (and that it was free to read online!1) was very exciting. It’s an absolutely incredible book, in which you learn about programming languages while implementing your own. The author describes himself as having been “bitten by the language bug years ago”.


Probably once a year, I end up back in the same discussion about timezones. I don’t like timezones and apparently I bring that up a lot. The Usual Griping Programmers' hatred for timezones is a bit of a meme. (I just googled “xkcd timezones” with absolute confidence there would be a comic, and of course I was right.) Computer systems don’t play nice with different times across the world. If I run a retail website, “weekend” sales should begin Saturday morning and end Sunday evening your time, even if it happens to mean that’s not the weekend where I am.

Is PyScript a Big Deal?

I went to PyCon a few weeks ago and while there, saw Peter Wang’s keynote on a new project called PyScript. PyScript is, essentially, a set of tools for running Python code in the browser – potentially even user-submitted code. I think that’s going to have a significant impact on the Python world, though maybe not in the way you’d first expect. Some Background For years now, various groups have been working on finding a way to “run” Python in the browser.

On the Road Trip

I recently returned from a 10-day road trip. Nowhere too exciting, just through the middle of the continental US: St. Louis, Memphis, northeast Arkansas, and Champaign (home of the University of Illinois Urbana-Champaign). People who know me probably wouldn’t describe me as the road trip type. But I had a few weeks off before I started a new job and the opportunity to travel without any commitments (or a finite amount of PTO) doesn’t present itself often; I figured that there would never be a better time to travel somewhat spontaneously.

Apartment Hunting with Python

I recently crossed the 9-month mark as a Chicago resident. The time has come for a big decision: renew my lease, or make the move to a new apartment?

I really like my current home. Two bedrooms, a back porch, a garage, and more grounded outlets than even a tech nerd like me could want. It’s in Little Italy, which is not a popular choice for Chicago young professionals, but is comfortable and has a decent set of restaurants. I suspect that a similar unit in a more “hip” neighborhood might be out of my price range. And my real office (as opposed to my extra bedroom, which has been serving in that capacity since I moved here) is a 10-minute bike ride away. The north side, home of many of those hip neighborhoods, would bring with it a commute at least twice as long.

On the other hand, my primary motivation in moving to a big city was exploration and experience. I wanted to get to know Chicago, particularly its neighborhoods. Moving would offer me a change of location, unlocking many new walkable or bikable destinations. Additionally, none of my friends live near my current apartment; most are in various parts of the northern neighborhoods, while I live somewhat south and west of the Loop (the downtown area of Chicago). Seeing most friends requires a 15+ minute drive or 30+ minute train ride.