hwo to have function to pick for list one time pick first index next pick last index code example

Example 1: last element of list python

>>> some_list = [1, 2, 3]
>>> some_list[-1] = 5 # Set the last element
>>> some_list[-2] = 3 # Set the second to last element
>>> some_list
[1, 3, 5]

Example 2: python last element of list

>>> list[-1:] # returns indexed value
    [3]
>>> list[-1]  # returns value
    3