[FIXED] Pandas groupby cumulative sum,mean,median based on the flag values

Issue

I need to calculate cumulative calculations (sum,mean,median,etc) based on the values of Indicator

It should do the calculations for all the false indicator and print it adjacent to the true. then calculated value should reset and start from true until true appears again for Indicator.

Input data frame

Amount	Indicator
10	False
20	False
5	True
8	False
4	False
6	True

output would be

Amount	Indicator	Sum	Mean
10	False
20	False
5	True	30	15
8	False
4	False
6	True	17	5.6

I tried to use groupby with cumsum() using Indicator as group , but have not had any luck yet.

Solution

In one go using only one groupby:

df[["Sum", "Mean"]] = np.NaN
df.loc[df.Indicator, ["Sum", "Mean"]] = (df.groupby(df.Indicator.cumsum())
                                         .agg({"Amount": ["sum", "mean"]})
                                         .shift(1).iloc[1:].values)

Answered By - bitflip