determine column maximum value per another column in pandas dataframe

Question

I have a dataframe contains location Id, store name and store revenue. I want to determine the store that has the maximum revenue per area

I wrote a code for that, but n

Answer 1

Create boolean mask by compare by eq (==) and convert it to integers - 0, 1 to False, True:

s = dframe.groupby("Loc_Id")["Revenue"].transform('max')
dframe["max_value"]= s.eq(dframe["Revenue"]).astype(int)
print (dframe)
   Loc_Id Store  Revenue  max_value
0       1     A       50          0
1       2     B       70          0
2       2     C       45          0
3       1     B       35          0
4       2     D       80          1
5       1     B       70          1
6       3     A       90          1
7       3     C       65          0