In my experience with Python, unit testing is essential to catch careless errors (typos, bad ducks, etc. that can't be caught by a linter) that would cause your program to crash at runtime, so there's a slightly different motivation for writing unit tests. It's a less restrictive language so you don't have the issues with private methods like the author mentioned, and is (at least to me) a bit less of a strain to write tests. Unit testing might correlate more with good hygiene for a Python codebase because testing is vital to check correctness and there are fewer situations where you have to mangle your code for the tests, whereas it may not in C# because you get guarantees from the type system that makes testing less vital and writing tests is more of a nuisance.