CODEWITHSUNDEEP
pythonpandas
Alex Man
Alex Man

Reputation: 477

Pandas dataframe group-by a modified index

I have following panda data-frame and I am trying to group it by Index1 column values after extracting the right hand side of the dash sign, i.e., z and y. 

Index1  Index2  Value
 a-z    1       10
 a-z    2       10
 a-z    1       4
 c-z    2       5
 c-z    1       9
 c-z    2       6
 a-z    1       6
 a-y    2       7
 b-y    1       8
 b-y    2       2
 c-y    1       9
 c-y    2       4

So the final result after using group-by sum should be something like this:

Index1  Index2  Value
z       1       29
z       2       21
y       1       17
y       2       13

Thanks a lot for your help.

Upvotes: 1

Views: 74

Answers (1)

harpan
harpan

Reputation: 8631

You can use:

df.groupby([df['Index1'].str[-1], df['Index2']])['Value'].sum().reset_index()

Output:

   Index1   Index2  Value
0    y        1      17
1    y        2      13
2    z        1      29
3    z        2      21

Upvotes: 2

Related Questions