It's the same for pretty much any language. There is nothing special about header files... > There’s no rule that they have to only contain declarations Same

It's the same for pretty much any language. There is nothing special about header files... > There’s no rule that they have to only contain declarations Same thing in Python, you can write statements at the top level of a module, and it will be executed whenever someone first import that module... > or that they have to appear at the top of source files Same thing in Python, you can `import` anywhere, and the context/order matters and overwrites existing scope declarations. > or that they have to be .h files Same thing in Python, the extension doesn't matter if you use import lib, only if you use the `import` keyword does the name/path matters.