pandas create new column conditional on other columns

1df['color'] = ['red' if x == 'Z' else 'green' for x in df['Set']]

1# For creating new column with multiple conditions
2conditions = [
3    (df['Base Column 1'] == 'A') & (df['Base Column 2'] == 'B'),
4    (df['Base Column 3'] == 'C')]
5choices = ['Conditional Value 1', 'Conditional Value 2']
6df['New Column'] = np.select(conditions, choices, default='Conditional Value 1')

1conditions = [
2    df['gender'].eq('male') & df['pet1'].eq(df['pet2']),
3    df['gender'].eq('female') & df['pet1'].isin(['cat', 'dog'])
4]
5
6choices = [5,5]
7
8df['points'] = np.select(conditions, choices, default=0)
9
10print(df)
11     gender      pet1      pet2  points
120      male       dog       dog       5
131      male       cat       cat       5
142      male       dog       cat       0
153    female       cat  squirrel       5
164    female       dog       dog       5
175    female  squirrel       cat       0
186  squirrel       dog       cat       0
19