Method to write and read a single N-Dimension numpy array to a .npy file.

Sample code

import numpy as np
#write a 3-dimension varaible trend38
np.save('indexes_trend38_sens_slope.npy',trend38)

#read the 3-dimention variable to trend38 (use different name is ok)
trend38=np.load('indexes_trend38_sens_slope.npy')

My original full version code:Indexes_ERA5_GreatLakesRegion_sens_slope.ipynb