if-then-else using numpy’s where()

pandas_if_else_then.py

import pandas as pd
df = pd.DataFrame({'AAA' : [4,5,6,7], 'BBB' : [10,20,30,40],'CCC' : [100,50,-30,-50]}); df
'''   
   AAA  BBB  CCC
0    4   10  100
1    5   20   50
2    6   30  -30
3    7   40  -50
'''

df['logic'] = np.where(df['AAA'] > 5,'high','low'); df
''' 
   AAA  BBB  CCC logic
0    4   10  100   low
1    5   20   50   low
2    6   30  -30  high
3    7   40  -50  high
'''