Python - change value of items within specific range

In this article, we would like to show you how to change value of items within specific range in Python.

Quick solution:

my_list = ['A', 'B', 'C', 'D']

my_list[1:3] = ['X', 'Y']

print(my_list)  # ['A', 'X', 'Y', 'D']

Practical example

Example 1

In this example, we change the values under index 1-3 (A, B) to X and Y.

my_list = ['A', 'B', 'C', 'D']

my_list[1:3] = ['X', 'Y']

print(my_list)  # ['A', 'X', 'Y', 'D']

Output:

['A', 'X', 'Y', 'D']

Note:

You may change the length of the list by inserting the number of items that doesn't match the number of replaced items.

Example 2

In this example, we change two values under 1-3 indexes (A, B) to the three new values (X,Y,Z). Notice that the length of our array will increase from 4 to 5.

my_list = ['A', 'B', 'C', 'D']

my_list[1:3] = ['X', 'Y', 'Z']

print(my_list)  # ['A', 'X', 'Y', 'Z', 'D']

Output:

['A', 'X', 'Y', 'Z', 'D']