How to swap columns of a given NumPy array?
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 Moduleimport 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 arraymy_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 Moduleimport numpy as np# Creating arraymy_array = np.arange(12).reshape(4, 3)print("Original Array : ")print(my_array)# creating function for swapdef Swap(arr, start_index, last_index): arr[:, [start_index, last_index]] = arr[:, [last_index, start_index]]# passing parameter into the functionSwap(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]]
