Summing and saving the values of column based on other column pandas

Question

df1 =

A        B
61880    7
62646    8
62651    9
62656    10
62783    11
61880    3
62646    2

I want to do data.groupby('A')['B'].sum() but in the way to save the result of "B" as a new column "B_updated" based on values of "A"

After data.groupby('A')['B'].sum() my output is:

A        B
61880    10
62646    10
...

It is good, but I can not perform further operations. Thus, I want to save "B" wrt "A". Because my next operation will be Math operations of column based on same values of other column pandas

you mean `df['B_updated']=df.groupby('A')['B'].transform('sum')` ?? — anky, Apr 19 '19 at 10:48
can you post the desired output please? or do you just require `data.groupby('A')['B'].sum().reset_index()` — anky, Apr 19 '19 at 10:55
@NazarTarlanli: Did you set the column or just run the right hand side of anky_91's solution? The indices will match up as you expect. — fuglede, Apr 19 '19 at 10:56
@anky_91 , seems good! I need to check and will inform in a comment! Thanks! — Nazar Tarlanli, Apr 19 '19 at 11:00
@fuglede, yes! I got a bit confused. Seems everything is working! I`m checking now — Nazar Tarlanli, Apr 19 '19 at 11:01

Chirag · Answer 1 · 2019-04-19T11:43:31.830

0

Try this:

x_df = df.groupby('A').size().reset_index(name='B_updated')
print(x_df)

edited Apr 19 '19 at 11:43

answered Apr 19 '19 at 11:41

Chirag

1 Answers1