[FIXED] Pandas averaging by specific row

Issue

I have table taht looks like following

A | B | C
__________
na| 1 | 2
3 | 3 | 4
na| 5 | 6
na| 7 | 8
2 | 9 | 10
na| 11| 12
na| 13| 14
3 | 15| 16

I would like to average all by column A. All the nan values till the number, final outcome should look like

A | B | C
__________
3 | 2 | 3
2 | 7 | 8
3 |13 |14

Solution

df = pd.DataFrame({'A':[pd.NA,3,pd.NA,pd.NA,2,pd.NA,pd.NA,3], 'B':range(1,16,2), 'C':range(2,17,2)})
df.assign(idx = [i if i in df.index[df.A.notna()] else pd.NA for i in df.index]).bfill().groupby('idx').mean().astype(int).reset_index(drop=True)

Output:

   A   B   C
0  3   2   3
1  2   7   8
2  3  13  14

Answered By - René