20190725 python 学习笔记 # ndarray 对象如何创建数组

创建数组

import numpy as np
a = np.array([1,2,3])
b = np.array([[1,2,3],[4,5,6],[7,8,9]])
b[1,1] = 10
print(a.shape)
print(b.shape)
print(a.dtype)
print(b)

运行结果：
(3,)
(3, 3)
int64
[[ 1 2 3]
[ 4 10 6]
[ 7 8 9]]