Combine two or more columns into a new column by row condition

Question

I would like to combine two or more columns into a new columns, based on the row condition ( which is 1, an integer ) the new columns should be a column contains joined string.<

Answer 1

Use:

final=df.assign(NEW=(df.dot(df.columns+',').str[:-1]))

---

       LAWSUIT  BOARD-MEETING                    NEW
index                                               
A            1              0                LAWSUIT
B            0              0                       
C            1              1  LAWSUIT,BOARD-MEETING
D            0              1          BOARD-MEETING

Answer 2

This is one of the few things that a for loop would be appropriate for in pandas

col_names = rdf.columns.tolist()
rdf["NEW"] = ""

for col in col_names:
    rdf.loc[rdf[col] == 1, "NEW"] = rdf.loc[rdf[col] == 1, "NEW"] + ("," + col)

rdf["NEW"] = rdf["NEW"].str.strip(",")

Answer 3

This could do the job

rdf['New'] = rdf.replace(1, pd.Series(rdf.columns+',', rdf.columns)).\
                                           replace(0, '').sum(axis = 1).\
                                           str.strip(',')