The problem Python has a Counter object – it’s found in the collections module – and I’ve become convinced that it’s… a bit weird? The basic idea is fine: it’s a dictionary but the keys are things you want to count, and the values are the amount of the thing you have counted. The neat thing is if you initialise a counter with an iterable like a string or a list, it’ll give you the counts for the number of times each element appears. Read more

I had this idea for a project I could do, but I thought “maybe I should do this other thing first to get to grips with the API”. I was doing something for that project, and got distracted doing a simpler project to learn about the technologies and tools involved. I got distracted from that project by some weird behaviour of a class in the python standard library (I’ll post about that later). Read more

In a previous post I said I would come back to explain a few somewhat opaque lines in my matrix-based solution to Advent of Code 2022, day 2. This is what I’m going to do here. There’s three smallish things I thought it was worth pointing out. None is going to surprise veteran python coders, but they might be of interest to some. Building matrices So the first line I want to look at is: Read more

I had a go at the first couple of weeks of problems from Advent of Code this year. I’ve posted my answers over here. I stopped after day 13 because the problems were getting harder but the time I had to devote to them could not increase. I hope to come back to them at some point. But today I wanted to point out something interesting about the day 2 puzzle. Read more

Let’s say you have a list, and you want to “interleave” or “riffle shuffle” the items in it. That is, you want to split the list in two, and then make a new list, alternating items from the first and second halves. In Python, there are a number of ways of doing this. Now we are left with the problem of which of these ways should we actually implement? One key factor in making this decision is performance: how well do the various methods actually perform. Read more