subtruction of columns in pandas

[garikhgh0]

I friends. I would like to ask how to orgnize subtruction of columns. so the dataframe is as below:

when I subtruct columns from each other I use the following code:

df['new'] = df.column_1 - df.column_2

but I need to subtract b from a, c from b and so on and combine(plus) the results in one column

df = pd.DataFrame(np.random.randint(low=0, high=10, size=(5, 5)),columns=['a', 'b', 'c', 'd', 'e'])

thanks in advance

a b c d e
6 5 6 8 3 
4 9 2 4 2 
1 7 9 4 3 
3 1 5 2 3 
2 8 3 5 7