[generallyfalse]

I see that you prefer not to use recurrency in Python. That decision is correct since python is not optimized for recurrency but it also can make the code more complex. See https://realpython.com/python-thinking-recursively/

On the other hand, using iterators in python is nice. You didn't use iterators to compute the sum of cubes, many problems can be solved in one line using iterators. https://www.datacamp.com/community/tutorials/python-iterator...

Perhaps your code should try to go from the easy cases to the complex cases in pattern matching.

As a hobby programmer I program without stress, if I was to make a living by programming I think I shouldn't enjoy so much.

I think you should read norvig post: http://norvig.com/21-days.html, also to learn to program in python: https://github.com/norvig/pytudes

I believe that in a year or two you could be prepared to judge your progress