Appending a GROUP BY result into original table

Question

 col = full.groupby('state')[['demVote']].mean()

full is the name of the original table. How would I append the results of this group by statement on to the original table full as a column called 'DEM'?

Pedro · Answer 1 · 2018-09-04T22:27:15.983

0

I think this will work, can you provide a specif example if not?

full['DEM'] = full.groupby('state').mean()['demVote']

edited Sep 04 '18 at 22:27

answered Sep 04 '18 at 22:17

Pedro

355
4
18

score 0 · Accepted Answer · answered Sep 04 '18 at 22:17

use transform:

full['DEM'] = full.groupby('state')['demVote'].transform('mean')

For example:

>>> full
   demVote state
0        1    ca
1        2    ca
2        3    ny
3        4    ny

full['DEM'] = full.groupby('state')['demVote'].transform('mean')

>>> full
   demVote state  DEM
0        1    ca  1.5
1        2    ca  1.5
2        3    ny  3.5
3        4    ny  3.5

Appending a GROUP BY result into original table

2 Answers2