What is a negative index in python?

• Python arrays & list items can be accessed with positive or negative numbers (also known as index).

   For instance our array/list is of size n, then for positive index 0 is the first index, 1 second, last index will be n-1. For negative index, -n is the first index, -(n-1) second, last negative index will be – 1. A negative index accesses elements from the end of the list counting backwards.

An example to show negative index in python.

>>> import array

>>> a= [1, 2, 3]

>>> print a[-3]

1

>>> print a[-2]

2

>>> print a[-1]

3