How to get a vecor column consisting of the derivative of one array column with respect to another column?

Question

Python

I have a two dimensional array

0.0, 1
1.0, 2
2.0, 3
2.5, 4

How to get a column vecor consisting of the derivative of the second column with respect to the first?

0
1
1
2

Or

1
1
2

Answer 1

np.diff(a[:, 1]) / np.diff(a[:, 0])