Small Lessons From Learning Pytest

I’ve been spending more time with pytest lately, and it’s been surprisingly eye‑opening. Writing tests forced me to look at my own function names with fresh eyes — suddenly 'nullable_rule(...)' didn’t make sense at all, but 'null_allowed_rule(...)' read clearly. I also bumped into a few pandas quirks along the way: 'bool' and 'boolean' are not the same thing, and 'None' in a Series is definitely not the same as an empty string. And then there’s parametrisation — such a simple feature, yet it makes tests cleaner, sharper, and far easier to reason about. It’s been a good reminder that testing isn’t just about catching bugs - it’s about understanding your code more deeply. What small testing discovery has surprised you lately?