Change Column Based on Other Column

import numpy as np
import pandas as pd
df = pd.read_csv('marks.csv')
df
student language science maths history
0 kumar 90 56 34 34
1 kevin 10 34 32 67
2 sammy 90 23 12 32
3 janice 20 67 90 45
4 peter 30 56 45 65
5 prem 90 45 45 34
6 carrol 50 90 45 23 
# Whoever got more than 40 marks in Maths, we will double their marks
df.loc[df.maths > 40, 'history'] = 2 * df['history']
df
student language science maths history
0 kumar 90 56 34 34
1 kevin 10 34 32 67
2 sammy 90 23 12 32
3 janice 20 67 90 90
4 peter 30 56 45 130
5 prem 90 45 45 68
6 carrol 50 90 45 46