PYTHON (PANDAS) Concatenate content of two rows on the last of these two rows

I’m struggling on concatenations of content of two rows into the last of these two rows.

Here my situation:

I would like something like

Could you please help me to reach this result?

Thanks in advance!

I tried the following:

df.iloc[1] = df_bo.iloc[0] + " " + df_bo.iloc[1]

but it gives me the following

IndexError: single positional indexer is out-of-bounds

I tried to transpose DF too, but it’s seems to be a bit sophisticated.

>Solution :

You can use stack to get rid of the NaNs, then groupby.agg to join the names:

df.iloc[1] = df.stack().groupby(level=1).agg(' '.join)

If you want to limit the input rows:

df.iloc[1] = df.iloc[:2].stack().groupby(level=1).agg(' '.join)

Output:

          A         B              C                   D
0       NaN       NaN          Rossi           Brambilla
1  Federico  Giovanni  Rossi Giorgio  Brambilla Marcello