Error: float object has no attribute notnull

Question

I have a dataframe:

  a     b     c
0 nan   Y     nan
1  23   N      3
2 nan   N      2
3  44   Y     nan

I wish to have this output:

Answer 1

You don't need apply, use np.where:

df['d'] = np.where(df.a.isnull(),
         np.nan,
         np.where((df.b == "N")&(~df.c.isnull()),
                  df.a*df.c,
                  df.a))

Output:

      a  b    c     d
0   NaN  Y  NaN   NaN
1  23.0  N  3.0  69.0
2   NaN  N  2.0   NaN
3  44.0  Y  NaN  44.0