how to collapse columns in pandas on null values?

Question

Suppose I have the following dataframe:

pd.DataFrame({\'col1\':    [\"a\", \"a\", np.nan, np.nan, np.nan],
            \'override1\': [\"b\", np.nan, \"b\",          


        

Answer 1

using ffill

df.ffill(1).iloc[:,-1]