How to swap columns of a given NumPy array?
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.
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 # orginal 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 ( "Orginal 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 :
Orginal 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]]
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