Lists and Indexing

Lists

A list defines a sequence of ordered objects (integers, floats, strings, and so on). They can be defined with comma-separated values between square brackets.

Indexing

Indexing means the fetching of a single value from the list. This is a 0-based indexing scheme: the first item sits at index 0, the second at index 1, and so on.

index	0	1	2	3	4
value	2	3	5	7	11
negative index	-5	-4	-3	-2	-1

Negative indices

Negative indices count from the end of the list. The last item is at index -1, the second to last at -2, and so on. They are a shortcut, saving you from writing L[len(L) - 1] just to reach the end.

Modifying a list

Indexing can be used to SET elements as well as access them. An index on the left of an equals sign replaces the item in that slot.