sort values and create new column based on result

I have this example

import pandas as pd
import numpy as np

rng = np.random.default_rng()
df = pd.DataFrame(rng.integers(0, 5, size=(5, 3)), columns=list("ABC"))
print(df)

which produce this dataframe

   A  B  C
0  4  4  7
1  1  9  6
2  2  9  1
3  0  5  8
4  3  5  5

i want to sort values from column A and B and C from higher to lower and put result column headers in new column D like this:

   A  B  C  D
0  4  4  7  C, A, B
1  1  9  6  B, C, A
2  2  9  1  B, A, C
3  0  5  8  C, B, A
4  3  5  5  B, C, A

I hope it’s clear, thank you

Answer

You can try:

df['D'] = df.apply(lambda x: ', '.join(x.sort_values(ascending=False).index), axis=1)


   A  B  C        D
0  4  4  7  C, B, A
1  1  9  6  B, C, A
2  2  9  1  B, A, C
3  0  5  8  C, B, A
4  3  5  5  C, B, A