How to subtract from previous row?

Question

I have a np.array stored in a variable, x , which looks like below:

array([[ 956],
       [ 929],
       [1083],
       [1074],
       [ 922]]

I want to subtract every number from the previous number, and I want a new variable, y , to look like below:

array([[ -27],
       [ 154],
       [  -9],
       [-152]]

Answer 1

import numpy as np 

x = np.array([[ 956],
       [ 929],
       [1083],
       [1074],
       [ 922]] 

out = np.diff(out, axis=0)

Out: array([[ -27],
   [ 154],
   [  -9],
   [-152]]