Given its name, I think the standard way should be delete:

import numpy as np

A = np.delete(A, 1, 0)  # delete second row of A
B = np.delete(B, 2, 0)  # delete third row of B
C = np.delete(C, 1, 1)  # delete second column of C

According to numpy’s documentation page, the parameters for numpy.delete are as follow:

numpy.delete(arr, obj, axis=None)

• arr refers to the input array,
• obj refers to which sub-arrays (e.g. column/row no. or slice of the array) and
• axis refers to either column wise (axis = 1) or row-wise (axis = 0) delete operation.