import numpy as np
import pandas as pd
s1 = pd.Series([1, 2, 3, 4], ['a', 'b', 'c', 'd'])
s2 = pd.Series([6, 3, 2, 1], ['d', 'c', 'b', 'a'])
print(s1)
print(s2)
s1+s2
s1 ** 2
s2 ** 2
s1 ** s2
s1 ** s1
s1['K'] = 7
s2['E'] = 9
print(s1)
print(s2)
s1+s2