[FIXED] Python pandas add N multiplied by the value of the current second and add with the value of N multiplied by the value of the previous second

Issue

I have a csv file in which I would like to make some calculation.

My csv looks something like this:

Time	Value1	Value2
10:00:00	4	1
10:00:01	5	0
10:00:02	4	4
10:00:03	5	3
10:00:04	4	1
10:00:05	5	2
10:00:06	4	4
10:00:07	5	8
10:00:08	4	4
10:00:09	5	8

In the background, I add the variable N = 10

And I would like to add a new column to the same csv file with a calculation using the formula

Something like N + 1 * Value 1 of its own line + N+ 1 * Value 2 of the previous line

To get something like this:

Time	Value1	Value2	Value3
10:00:00	4	1	44
10:00:01	5	0	66
10:00:02	4	4	44
10:00:03	5	3	99
10:00:04	4	1	77
10:00:05	5	2	66
10:00:06	4	4	66
10:00:07	5	8	99
10:00:08	4	4	132
10:00:09	5	8	99

I tried something like

out = df.groupby(['Time']) out = %N+1 * df['Value1'] + %N+1 * df['Value2']

But it doesn't quite work

Solution

import pandas as pd

df = pd.DataFrame(
    [['10:00:00', 4, 1], ['10:00:01', 5, 0]],
    columns=['Time', 'Value1', 'Value2']
)

N = 10
df['Value3'] = (N + 1) * (df.Value1 + df.Value2.shift(1))
print(df)

prints

index	Time	Value1	Value2	Value3
0	10:00:00	4	1	NaN
1	10:00:01	5	0	66.0

Answered By - Michael Hodel