numpy(0) 数组定义

定义递增数组

import numpy as np
np.arange(12)

array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])

np.zeros(8)

array([0., 0., 0., 0., 0., 0., 0., 0.])

[-2] 倒数第二个元素

参考：
[1] NumPy简明教程（二、数组1） https://blog.csdn.net/sunny2038/article/details/9002531
[2] https://www.runoob.com/numpy/numpy-array-from-numerical-ranges.html
[3] https://www.runoob.com/numpy/numpy-array-creation.html