After Grouping ..Sum of a column values based on the groups in pandas dataframe

Question

After grouping the column of the pandas dataframe how to do sum of another column of a dataframe based on the groups created.

df = df.groupby(by=['First'])

My dataframe:

First  Second

A      5
       6
       10
B      4
       5

expected dataframe:

First  Second

A      21
B      9

Possible duplicate of [Pandas group-by and sum](https://stackoverflow.com/questions/39922986/pandas-group-by-and-sum) — Ben.T, Jul 16 '19 at 18:18
Can you add df.to_dict() to this question? You input dataframe printed here is ambiguous. — Scott Boston, Jul 16 '19 at 18:23
`'A'` of `First` corresponding to `5, 6, 10` in column `Second`, so its sum value of `Second` must be `21`. Why your output shows it as `11` ? — Andy L., Jul 16 '19 at 18:57

MBA Coder · Answer 1 · 2019-07-16T20:25:33.957

1

df= df.groupby(['First'])['Second'].sum().reset_index()

I noticed you are missing a ' in your code, it might have been causing you issues before.

edited Jul 16 '19 at 20:25

answered Jul 16 '19 at 18:55

MBA Coder

1 Answers1