python如何像matlab一样使用向量化替代for循环

调用numpy 利用下标索引，批量查询

import numpy as np
a = list([1,2,3,4,5, 6, 7, 8])
b=np.array([2,3,7], dtype = int)
a = np.array(a,dtype=float)
print('\n')
print(f'a = {a}')
print(f'b = {b}')
print(f'a[b] = {a[b]}')

输出结果：

a = 1. 2. 3. 4. 5. 6. 7. 8.

b = 2 3 7

ab = 3. 4. 8.