Earlier quoted context omitted.
You can look at the source yourself. I don't understand either, randomly opening parts of both the Python and C++ and it's certainly not complicated and they write the Python in a C style anyway. I'm not a C++ coder and I only play with Python now and then, but can't say the code impressed me much. It's actually pretty hard to skim the code because it's massively over-commented and there are far too many tiny 2-line…
In general, abstracting code out into functions can be useful, even when the new functions is only called once. That is because functions are a well understood abstraction. And having code separated into functions makes it easier for the reader to deduce the coupling points: two blocks of code after another can have all kinds of weird dependencies, e.g. the first blog might set some local variables that the second on…
I've found in my experience working with other people's code and maintaining large code bases you find that overly nesting functions causes a lot of problems when you're trying to read or debug code.
You often also see problems where the essentially dependant functions start to separate in the code as people accidentally add new functions between them.
The article I linked is good, John describes it well. It's a nightmare to work with when you get triple or quadruple nesting of tiny functions, like in the code of this program. It's totally unnecessary.