Python - Numpy Array Column Deletion
Last Updated :
03 Apr, 2023
Given a numpy array, write a programme to delete columns from numpy array. Examples -
Input: [['akshat', 'nikhil'], ['manjeeet', 'akash']]
Output: [['akshat']['manjeeet']]
Input: [[1, 0, 0, 1, 0], [0, 1, 2, 1, 1]]
Output: [[1 0 1 0][0 2 1 1]]
Given below are various methods to delete columns from numpy array. Method #1: Using np.delete()
Python3
# Python code to demonstrate
# deletion of columns from numpy array
import numpy as np
# initialising numpy array
ini_array = np.array([[1, 0, 0, 1, 0],
[0, 1, 2, 1, 1]])
# deleting second column from array
result = np.delete(ini_array, 1, 1)
# print result
print ("Resultant Array :"+str(result))
Output:
Resultant Array :[[1 0 1 0]
[0 2 1 1]]
Time Complexity: O(n)
Space Complexity: O(n)
where n is length of array
Method #2: Using compress() and logical_not()
Python3
# Python code to demonstrate
# deletion of columns from numpy array
import numpy as np
# initialising numpy array
ini_array = np.array([[1, 0, 0, 1, 0], [1, 2, 0, 0, 1]])
z = [False, True, False, False, False]
# deleting second column from array
result = ini_array.compress(np.logical_not(z), axis = 1)
# print result
print ("Resultant Array :"+str(result))
Output:
Resultant Array :[[1 0 1 0]
[1 0 0 1]]
Time Complexity: O(n)
Space Complexity: O(n)
where n is length of array
Method #3: Using logical_not()
Python3
# Python code to demonstrate
# deletion of columns from numpy array
import numpy as np
# initialising numpy array
ini_array = np.array([[1, 0, 0, 1, 0], [1, 2, 0, 0, 1]])
z = [False, True, False, False, False]
# deleting second column from array
result = ini_array[:, np.logical_not(z)]
# print result
print ("Resultant Array :"+str(result))
Output:
Resultant Array :[[1 0 1 0]
[1 0 0 1]]
Time Complexity: O(n)
Space Complexity: O(n)
where n is length of array
Similar Reads
NumPy Array in Python NumPy (Numerical Python) is a powerful library for numerical computations in Python. It is commonly referred to multidimensional container that holds the same data type. It is the core data structure of the NumPy library and is optimized for numerical and scientific computation in Python. Table of C
2 min read
Delete a CSV Column in Python The comma-separated values ​​(CSV) file is a delimited text file that uses commas for individual values. Each line of the file is a data record in CSV. This format used for tabular data, rows, and columns, exactly like a spreadsheet. The CSV file stores data in rows and the values ​​in each row are
3 min read
numpy.delete() in Python The numpy.delete() function returns a new array with the deletion of sub-arrays along with the mentioned axis.  Syntax: numpy.delete(array, object, axis = None) Parameters : array : [array_like]Input array. object : [int, array of ints]Sub-array to delete axis : Axis along which we want to delete
3 min read
Python | Convert Numpy Arrays to Tuples Given a numpy array, write a program to convert numpy array into tuples. Examples - Input: ([[1, 0, 0, 1, 0], [1, 2, 0, 0, 1]]) Output: ((1, 0, 0, 1, 0), (1, 2, 0, 0, 1)) Input: ([['manjeet', 'akshat'], ['nikhil', 'akash']]) Output: (('manjeet', 'akshat'), ('nikhil', 'akash')) Method #1: Using tuple
2 min read
Python Lists VS Numpy Arrays Here, we will understand the difference between Python List and Python Numpy array. What is a Numpy array?NumPy is the fundamental package for scientific computing in Python. Numpy arrays facilitate advanced mathematical and other types of operations on large numbers of data. Typically, such operati
7 min read