Numpy(ndarray常用函数介绍）

1. 由list创建ndarray

1 import numpy as np
2 
3 x = [1, 2, 3]
4 print(x)
5 print(type(x))
6 a = np.array(x)
7 print(a)
8 print(type(a))

output: 

[1, 2, 3]

<class 'list'>

[1, 2, 3]

<class 'numpy.ndarray'>