Operations on Lists

Modifying elements in a list using indices

You have learned how to define lists and how to access each element in a list using indices. Using these indices, you can also modify the element present in the list. For example, let us define a list of floating point values as follows:

>>> wages = [40.25, 51.5, 35.4, 42.34]

Now, if we want to modify the value at index 2 in this list from 35.4 to 38.5 then we can do it as follows:

>>> wages[2] = 38.5

If you print the list wages now, then you see that the element at index 2 has been modified.

>>> wages
[40.25, 51.5, 38.5, 42.34]

[40.25, 51.5, 38.5, 42.34]

List Concatenation and List Replication

Similar to Strings, we can perform concatenation of two different lists using the + operator in order to create a combined list. And if we want to replicate the list a specific number of times then we can use the * operator along with an integer that represents how many times you want the list to be replicated.

>>> new_wages = wages + [39.2, 41.5]
>>> new_wages
[40.25, 51.5, 35.4, 42.34, 39.2, 41.5]

>>> new_wages

[40.25, 51.5, 35.4, 42.34, 39.2, 41.5]

Here, we have combined the list wages and another list containing two values into a new list new_wages with the help of the + operator.

>>> replicated_wages = wages * 2
>>> replicated_wages
[40.25, 51.5, 35.4, 42.34, 40.25, 51.5, 35.4, 42.34]

Here, we have replicated the elements in the list wages twice using the * operator followed by the integer 2.