*239*

You can use the following basic syntax to swap two columns in a NumPy array:

**some_array[:, [0, 2]] = some_array[:, [2, 0]]
**

This particular example will swap the first and third columns in the NumPy array called **some_array**.

All other columns will remain in their original positions.

The following example shows how to use this syntax in practice.

**Related:** How to Swap Two Rows in a NumPy Array

**Example: Swap Two Columns in NumPy Array**

Suppose we have the following NumPy array:

**import numpy as np
#create NumPy array
some_array = np.array([[1, 1, 2], [3, 3, 7], [4, 3, 1], [9, 9, 5], [6, 7, 7]])
#view NumPy array
print(some_array)
[[1 1 2]
[3 3 7]
[4 3 1]
[9 9 5]
[6 7 7]]**

We can use the following syntax to swap the first and third columns in the NumPy array:

**#swap columns 1 and 3
some_array[:, [0, 2]] = some_array[:, [2, 0]]
#view updated NumPy array
print(some_array)
[[2 1 1]
[7 3 3]
[1 3 4]
[5 9 9]
[7 7 6]]
**

Notice that the first and third columns have been swapped.

All other columns remained in their original positions.

**Additional Resources**

The following tutorials explain how to perform other common tasks in NumPy:

How to Remove Duplicate Elements in NumPy Array

How to Replace Elements in NumPy Array

How to Rank Items in NumPy Array