Create a new column in Pandas dataframe

Import modules

import pandas as pd

  Create some dummy data

raw_data = {'name': ['Willard Morris', 'Al Jennings', 'Omar Mullins', 'Spencer McDaniel'],
'age': [20, 19, 22, 21],
'favorite_color': ['blue', 'blue', 'yellow', "green"],
'test_one': [88, 92, 95, 70],
'test_two': [78, 100, 90, 85]}
df = pd.DataFrame(raw_data)
df

	age	favorite_color	name	test_one	test_two
0	20	blue	Willard Morris	88	78
1	19	blue	Al Jennings	92	100
2	22	yellow	Omar Mullins	95	90
3	21	green	Spencer McDaniel	70	85

df['test_average'] = (df.test_one + df.test_two)/2
df.head()

	age	favorite_color	name	test_one	test_two	test_average
0	20	blue	Willard Morris	88	78	83.0
1	19	blue	Al Jennings	92	100	96.0
2	22	yellow	Omar Mullins	95	90	92.5
3	21	green	Spencer McDaniel	70	85	77.5