# How to swap columns of a given NumPy array?

• Last Updated : 22 Jun, 2021

In this article, let’s discuss how to swap columns of a given NumPy array.

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Approach :

• Import NumPy module
• Create a NumPy array
• Swap the column with Index
• Print the Final array

Example 1: Swapping the column of an array.

## Python3

 `# importing Module``import` `numpy as np`  `# creating array with shape(4,3)``my_array ``=` `np.arange(``12``).reshape(``4``, ``3``)``print``(``"Original array:"``)``print``(my_array)` `# swapping the column with index of``# original array``my_array[:, [``2``, ``0``]] ``=` `my_array[:, [``0``, ``2``]]``print``(``"After swapping arrays the last column and first column:"``)``print``(my_array)`

Output :

```Original array:
[[ 0  1  2]
[ 3  4  5]
[ 6  7  8]
[ 9 10 11]]
After swapping arrays the last column and first column:
[[ 2  1  0]
[ 5  4  3]
[ 8  7  6]
[11 10  9]]```

Example 2: Swapping the column of an array with the user chooses.

## Python3

 `# Importing Module``import` `numpy as np`  `# Creating array``my_array ``=` `np.arange(``12``).reshape(``4``, ``3``)``print``(``"Original Array : "``)``print``(my_array)``# creating function for swap` `def` `Swap(arr, start_index, last_index):``    ``arr[:, [start_index, last_index]] ``=` `arr[:, [last_index, start_index]]` `# passing parameter into the function``Swap(my_array, ``0``, ``1``)``print``(``" After Swapping :"``)``print``(my_array)`

Output :

```Original Array :
[[ 0  1  2]
[ 3  4  5]
[ 6  7  8]
[ 9 10 11]]
After Swapping :
[[ 1  0  2]
[ 4  3  5]
[ 7  6  8]
[10  9 11]]```

My Personal Notes arrow_drop_up