How to swap columns of a given NumPy array?
Last Updated : 22 Jun, 2021
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In this article, let's discuss how to swap columns of a given NumPy array.
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.
# 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.
# 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]]
