Python is great as a dynamic language, but I find very few things about are easy to reason conclusively about because the state of the running program can be so

Python is great as a dynamic language, but I find very few things about are easy to reason conclusively about because the state of the running program can be so crazy (has pros and cons). But it probably depends at what level you are working in python and how deeply you understand it. Type checking and linting help a lot to keep the truly crazy contained, but it's just fundamentally a very difficult system to trust. Not to mention working around the GIL is fairly inefficient.