Python: Replace Value at Specific Index in List and Array

You can replace a value at a specific index in a list in Python by using direct indexing.

The basic syntax for replacing a value at a specific index using direct indexing:

# replacing the value at index 3 (remember in python index start at 0)
ex_list[3] = 100

The following examples demonstrate replacing a value at a specific index in a list or array in Python.

Replace value at a specific index in list

Create an example list,

ex_list = [10, 20, 30, 40, 50, 60]

Replace a value 30 (which is at index 2) with 300,

ex_list[2] = 300

print(ex_list)

# ouput
[10, 20, 300, 40, 50, 60]

You can see that we replaced the value 30 at index 2 with 300 in a list in Python.

Replace value at a specific index in numpy array

Create an example array,

# import package
import numpy as np

ex_array = np.array([10, 20, 30, 40, 50, 60])

Replace a value 30 (which is at index 2) with 300 in numpy array,

ex_array[2] = 300

print(ex_array) 

# output
[ 10  20 300  40  50  60]

You can see that we replaced the value 30 at index 2 with 300 in a numpy array in Python.