Groupby pandas dataframe 具有相同值的两列

Question

I want to groupby two column with the same value in 'A' and 'B' and make a cumsum based on which column is located that value.

Example of grouped dataframe for a values

   A  B  ValueA  ValueB
0  b  a       1       3
1  c  a       2       2
2  a  b       2       4

Now, if the value is in column 'A' consider ValueA to cumsum if the value is in column 'B' consider ValueB to cumsum

EDIT: I would to perform shift().rolling() just like cumsum , I tried to put it after groupby but result is not correct.

Code

from numpy.core.numeric import NaN

df = pd.DataFrame({
    'A' : ['b','c','a','c','a','c','b','c'],
    'B': ['a', 'a', 'b', 'b','c','a','a','b'],
    'ValueA':[1,2,2,1,2,4,7,1],
    'ValueB':[3,2,4,3,1,2,4,5]
})
print(df)

df[['sumA','sumB']] = (
    df[['ValueA','ValueB']].stack(dropna=False)
      .groupby(df[['A','B']].stack().tolist())
      .cumsum()
      .unstack()
)
print(df)

#groupby(...).shift().rolling(2, min_periods=2).sum()

df['Expected_Shift_RollingA'] = [NaN,NaN,5,NaN,4,2,7,5]
df['Expected_Shift_RollingB'] = [NaN,NaN,NaN,5,3,4,4,10]
print(df)

Answer 1

You can do with stack the values columns, use groupby on the column AB stacked, then cumsum and unstack to be back original shape

df[['sumA','sumB']] = (
    df[['ValueA','ValueB']].stack()
      .groupby(df[['A','B']].stack().tolist())
      .cumsum()
      .unstack()
)
print(df)
   A  B  ValueA  ValueB  sumA  sumB
0  b  a       1       3     1     3
1  c  a       2       2     2     5
2  a  b       2       4     7     5
3  c  b       1       3     3     8

EDIT: after reviewing the original data, some Values are missing, so one need to adjust the above method.

By either filling the missing values by 0.

df[['ValueA','ValueB']].fillna(0).stack()
  .groupby(...

or keeping the nan while stack so.

df[['ValueA','ValueB']].stack(dropna=False)
  .groupby(...