Using conditional to generate new column in pandas dataframe

Question

I have a pandas dataframe that looks like this:

   portion  used
0        1   1.0
1        2   0.3
2        3   0.0
3        4   0.8

I\'d

Answer 1

df['TaxStatus'] = np.where(df.Public == 1, True, np.where(df.Public == 2, False))

This would appear to work, except for the ValueError: either both or neither of x and y should be given