With a Python list, ... By default this is 1, so the slice retains every element from the list it’s slicing from. Set step to 2, and you’ll select every second element, and so on.

For instance, a list can’t be a key, because elements can be added to or removed from a list. Likewise, a dictionary itself can’t be a key for the same reason.

There is a phenomenon in the Python programming language that affects the efficiency of data representation and memory. I call it the "invisible line." This invisible line might seem innocuous at ...