许多一元运算是作为ndarray类的方法提供的。这包括sum，min，max等。这些函数也可以通过设置轴参数按行或列方式应用。

# Python program to demonstrate

# unary operators in numpy

import numpy as np

arr = np.array([[1, 5, 6],

[4, 7, 2],

[3, 1, 9]])

# maximum element of array

print ("Largest element is:", arr.max())

print ("Row-wise maximum elements:",

arr.max(axis = 1))

# minimum element of array

print ("Column-wise minimum elements:",

arr.min(axis = 0))

# sum of array elements

print ("Sum of all array elements:",

arr.sum())

# cumulative sum along each row

print ("Cumulative sum along each row:\n",

arr.cumsum(axis = 1))