numpy array length

import numpy as np

arr = np.array([1, 2, 3, 4])
arr_2D = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])

print(arr.ndim)
print(arr_2D.ndim)

np_array.size

>>> x = np.zeros((3, 5, 2), dtype=np.complex128)
>>> x.size
30
>>> np.prod(x.shape)
30