Map is a common way to transform lists in most programming languages. In Python, map is a function that loops over a list and applies a function (that you provide) to each item. Your function receives ...

For example, using an index of -1 is a handy way to grab the last item from a list no matter the size of the list. In that case, list_of_ints[-1] yields 3 , and list_of_objects[-1] yields None .

In Python, the most common of these data types is called the "list." The list is a zero-indexed collection of data of any type, stored linearly: the first item is at index 0, the second at index 1 ...