df['PRODUCT'] = np.where(df['TYPE'] == '2b', 'Pencil',
                np.where(df['TYPE'] like 'I5%', 'Ruler', 0))

df['PRODUCT'] = np.where(df['TYPE'] == '2b', 'Pencil',
                np.where('I5' in df['TYPE'], 'Ruler', 0))

df['PRODUCT'] = np.where(df['TYPE'] == '2b', 'Pencil',
                np.where(df['TYPE'].str.contains('I5'), 'Ruler', 0))