On #3 “slicing”, on a related note for Python, remember after a new list is created from slicing, each element/item in the new list is the exact reference to th

On #3 “slicing”, on a related note for Python, remember after a new list is created from slicing, each element/item in the new list is the exact reference to the corresponding element/item in the original list. This is espeically problematic when you try to do things on a mutuable object in either list, but expect the other list remains completely shield from change. You have to do deepcopy (but for immutable object deepcopy has no effect). Makes sense and probably is a given for most programming languages.