import pandas as pd import numpy as np df = pd.DataFrame(np.array([[1, 2], [4, 5], [7, 8]]), columns=['a', 'b']) df.head() # a b # 0 1 2 # 1 4 5 # 2 7 8 df['c'] = eval( "df['a'] + df['b']" ) df.head() # a b c # 0 1 2 3 # 1 4 5 9 # 2 7 8 15