python：将numpy array中的NaN替换为某个数值

import numpy as np

a = np.array([[0.5,np.nan,2.5],[-0.5,0.5,1.5],[-1.5,-0.5,0.5],[-3,-2,-1]])

print(np.isnan(a))

a[np.isnan(a)] = 1.5
print(a)