np array extend code example

Example 1: how to extend array in numpy

array1=np.array([[1,1,1],[2,2,2],[3,3,3]])
#syntax for appending elements to an array-> np.append(name_of_the array, elements, axis)
#along a row, the axis is 0
array1=np.append(array1, ([[4,4,4],[5,5,5]]), 0)
#along a cloumn, the axis is 1 
array1=np.append(array1, ([[1],[2],[3],[4],[5]]),1)

Example 2: np append row

A= [[1, 2, 3], [4, 5, 6]]
np.append(A, [[7, 8, 9]], axis=0)

    >> array([[1, 2, 3],
              [4, 5, 6],
              [7, 8, 9]])
#or 
np.r_[A,[[7,8,9]]]

Example 3: numpy python add array

x1 = [1, 2]
x2 = [1, 2]
print(np.add(x1, x2))
# [2, 4]