Or rather, focus on the big things. Algorithmic complexity etc. Also for all languages where you want to do performance work: Learn to use a profiler, so you c

Or rather, focus on the big things. Algorithmic complexity etc. Also for all languages where you want to do performance work: Learn to use a profiler, so you can find the things that matter. And then selectively look what you can improve there. Even in Python, some hacks or slightly unergonomic patterns in a really hot loop can be worth a lot.