Prerequisite: Numpy module
The following article discusses how we can access different columns of multidimensional Numpy array. Here, we are using Slicing method to obtain the required functionality.
Example 1: (Accessing the First and Last column of Numpy array)
Python3
# Importing Numpy module import numpy as np # Creating a 3x3 Numpy array arr = np.array([[11, 20, 3], [89, 5, 66], [71, 88, 39]]) print("Given Array :") print(arr) # Access the First and Last column of array res_arr = arr[:,[0,2]] print("\nAccessed Columns :") print(res_arr) |
Output:
Given Array :
[[11 20 3]
[89 5 66]
[71 88 39]]
Accessed Columns :
[[11 3]
[89 66]
[71 39]]
Example 2: (Accessing the Middle and Last column of Numpy array)
Python3
# Importing Numpy module import numpy as np # Creating a 4x4 Numpy array arr = np.array([[1, 20, 3, 1], [40, 5, 66, 7], [70, 88, 9, 11], [80, 100, 50, 77]]) print("Given Array :") print(arr) # Access the Middle and Last column of array res_arr = arr[:,[1,3]] print("\nAccessed Columns :") print(res_arr) |
Output:
Given Array :
[[ 1 20 3 1]
[ 40 5 66 7]
[ 70 88 9 11]
[ 80 100 50 77]]
Accessed Columns :
[[ 20 1]
[ 5 7]
[ 88 11]
[100 77]]
Example 3: (Accessing the Last two columns of Numpy array)
Python3
# Importing Numpy module import numpy as np # Creating a 3d (3X4X4) Numpy array arr = np.array([[[21, 20, 3, 1], [40, 5, 66, 7], [70, 88, 9, 11], [80, 100, 50, 77]], [[65, 120, 53, 73], [49, 50, 56, 11], [81, 88, 34, 22], [564,56, 76, 99]], [[45, 85, 38, 455], [40, 53, 69, 6], [50, 528, 654, 11], [54, 87, 78, 77]]]) print("Given Array :") print(arr) # Access the Last two columns of array res_arr = arr[2,:,[2,3]] print("\nAccessed Columns :") print(res_arr) |
Output:
Given Array :
[[[ 21 20 3 1]
[ 40 5 66 7]
[ 70 88 9 11]
[ 80 100 50 77]]
[[ 65 120 53 73]
[ 49 50 56 11]
[ 81 88 34 22]
[564 56 76 99]]
[[ 45 85 38 455]
[ 40 53 69 6]
[ 50 528 654 11]
[ 54 87 78 77]]]
Accessed Columns :
[[ 38 69 654 78]
[455 6 11 77]]
Example 4: (Accessing the First column of a 4D Numpy array)
Python3
# Importing Numpy module import numpy as np # Creating a 4D Numpy array arr = np.array([ [ [ [1,2], [3,4] ], [ [5,6], [7,8] ] ], [ [ [9,10], [11,12] ], [ [13,14], [15,16] ] ] ]) print("Given Array :") print(arr) # Access the First three columns of array res_arr = arr[0,0,:,[0]] print("\nAccessed Columns :") print(res_arr) |
Output:
Given Array :
[[[[ 1 2]
[ 3 4]]
[[ 5 6]
[ 7 8]]]
[[[ 9 10]
[11 12]]
[[13 14]
[15 16]]]]
Accessed Columns :
[[1 3]]
