Good Morning from my Robotics Lab! This is Shadow_8472 and today, the month of bot development concludes. Be sure to catch the previous posts before reading this one. Let’s get started!
Measures of Progress
Progress this week towards the bot while substantial, wasn’t anything special. In fact, the last day I had to work on it was mostly a flop of me goofing off on other pursuits instead of focusing. Instead, I’d like to focus on what I’ve accomplished over the month.
This longer push on the bot built upon a dice bot I programmed up several months ago that understood how to roll X dice with N sides. Over the month, I achieved multiple personal firsts and worked on my coding style. It was always satisfying when I came up with a new or clever trick to reduce code complexity for a given job. I learned a thing or two about coding the “right” way and practiced with Git version control software.
Memorable Milestones and Personal Firsts
The first big milestone that sticks out in retrospect was rewriting the dice rolling engine from scratch. I will likely want to make another dice bot geared for another game in the future. By splitting out related functions of a larger project into separate files, I can almost trivially re-use the code in another project or re-implement the whole thing. Shorter source files are also much easier to navigate and maintain.
Code condensation is fun. It hurts to see a piece of code you spent all day hacking together (successfully) to be replaced in five minutes by a stupidly more efficient approach, but simpler is easier to maintain. I found myself going through my code more than a few times as I learned about the likes of fstrings and the enumerate function to make sure they were being used when they made more sense than old standards or contextually strayed code, respectively.
This week in particular, I noticed how my relationship with exceptions has changed over the long term. As a beginning programmer in high school, exceptions and tracebacks always meant the existence of a bug. As I became more experienced (one of my early blog projects), I encountered a programming problem where the only way I could solve it was to try/catch an exception. On this project, I have a few places where I reached for try/except almost as though it were an if/else statement. I’ve even made use of Python’s ability to manage different kinds of exceptions with different code blocks in a new feature I worked on this week (but haven’t finished as of writing).
Saving and Loading Data
I have next to zero practical knowledge of writing programs with save data. I was able to bodge a webcam subtitle program involving a second webcam and writing text to a file, but that’s it from before this week.
Fancy dice bots have the ability to store information about players and characters involved in a game. My group don’t strictly need this feature to play, but it is high up on the nice-to-have list. Plus this is a skill I am after; it was just so intimidatingly long to research! Modules like Pickle and Shelve that dump data directly into a file warn in their documentation that clever users can inject arbitrary code through clever wording if the programmer isn’t careful. I started with a module called “configParser,” before realizing this wasn’t exactly its intended use case. It’s close enough though, but it still took a while to gain a mental model of how it operates internally – with an object in RAM, and not directly on the disk. Write the object to essentially a plaintext file, and it can be read back fairly simply. As an important bonus, the saved files are human readable.
Again, saving data to files is perfectly safe. It’s important though to be careful when loading naively stored user-generated data. While researching, I learned about a 15 year-old, trivially exploited vulnerability in the tarfile module that circulated in the news last week. The moral: know what you’re loading, and sanitize incoming data from users or directly from the Internet before saving it.
Takeaway
Sometimes, you need to look at something ten or more times before things start making more sense than not. Programming takes time to learn. One new technique I tried out this week (but wasn’t able to use) is called Ternary Operators. These look like if/else statements nestled into a single line, but they’re more for when you have multiple variations on a single command. My to-do list on this project is quite lengthy as I still need to diagnose why my newest feature collapsed on me. I wish I could end the month with everything in a working state, but such as it is, I have other things I need to work on too.
Final Question
What is your most ambitious personal project to date?