text numpy.padについてref：https：//qiita.com/naivete5656/items/3613ac106b1eb71aaf4a

Posted 2021-05-02

import numpy as np 
img=np.asarray([[1,2,3],[4,5,6],[7,8,9]])
print(np.pad(img,((0,0),(1,1)),'constant',constant_values=0))
print(np.pad(img,((1,1),(0,0)),'constant',constant_values=0))
print(np.pad(img,1,'constant',constant_values=0))

[[0 1 2 3 0]
 [0 4 5 6 0]
 [0 7 8 9 0]]
[[0 0 0]
 [1 2 3]
 [4 5 6]
 [7 8 9]
 [0 0 0]]
[[0 0 0 0 0]
 [0 1 2 3 0]
 [0 4 5 6 0]
 [0 7 8 9 0]
 [0 0 0 0 0]]