Whenever you leave the C code that Python happens to use like actually looping over an array it's slow. Python is in fact an _abstraction inversion_ , primitive operations are slow and high level operations are fast (because they can avoid Python's slow VM) and so you need to use premade libraries for everything. In Nim it's the opposite, primitive operations are fast and custom code wins over premade libraries quite often because custom code is specialized for the task at hand.
**That 's the fundamental lesson to learn when coming from Python.** Surely we can and will improve the rough edges you encountered but it won't change the fundamental lesson.
