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

Question

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

Here my situation:

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

I would like something like

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

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.

Asked By: Federico Poggio

||

Source

Answer 1

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

Answered By: mozway

Answer 2

If the original dataframe is df, this should work. 🙂

df2 = pd.concat([df.iloc[:1, :], pd.DataFrame(df.T[0] + ' ' + df.T[1]).T])

Answered By: MattiH

Answer 3

df1.loc[1,["C","D"]]=df1.loc[:,["C","D"]].agg(" ".join).tolist()
df1

out

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

Answered By: G.G

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

Question:

Answers: