CODE EXAMPLE FOR PYTHON

pandas set condition multi columns

conditions = [
   .....:     (df['col2'] == 'Z') & (df['col1'] == 'A'),
   .....:     (df['col2'] == 'Z') & (df['col1'] == 'B'),
   .....:     (df['col1'] == 'B')
   .....: ]
   .....: 

In [214]: choices = ['yellow', 'blue', 'purple']

In [215]: df['color'] = np.select(conditions, choices, default='black')

In [216]: df
Out[216]: 
  col1 col2   color
0    A    Z  yellow
1    B    Z    blue
2    B    X  purple
3    C    Y   black