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

This could do the job

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