I think comparing unit tests to a robust type system is a good way to think about typed languages. In my experience, unit tests most often catch NPEs, which a type system also does. The automated refactoring that can be done with a good type system is crazy.

Python has its place in a programmers tool belt, but I often ask questions to determine the language to use. How long lived will this code base be? How critical will be every ms of performance? How many LoC will the final product be? How many people will work inside this project? How dense and complex is the system to be built?

Python is incredible at short, utilitarian scripts that perform a single task that is not normally done inside of your main code base. It’s robust library collection lets you easily do things that other languages would need to be built from scratch. A short script to scrape twitter or analyze data can provide an enormous amount of value for time invested.