Python Padding

B=np.pad(A,((上1, 下2),(左3, 右4)),'constant',constant_values = (0,0))

A = np.arange(1,5).reshape(2,2)
print(A)

[[1 2]
 [3 4]]

B=np.pad(A,((1,2),(3,4)),'constant',constant_values = (0,0))
print(B)

[[0 0 0 0 0 0 0 0 0]
 [0 0 0 1 2 0 0 0 0]
 [0 0 0 3 4 0 0 0 0]
 [0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0]]