pandas多個Series運算和單個Series運算

代碼示例：

import pandas as pd
import numpy as np

#多個Series計算，相同索引的元素進行計算，隻有一個索引的元素結果均為NaN。注意計算後元素類型會發生變化
series1 = pd.Series([5,6,7,8],['A','B','D','E'])
print(series1)
'''
列印：
A    5
B    6
D    7
E    8
dtype: int64
'''
series2 = pd.Series([2,3,4,4],['A','C','E','F'])
print(series2)
'''
列印：
A    2
C    3
E    4
F    4
dtype: int64
'''
print(series1-series2)
'''
列印：
A    3.0
B    NaN
C    NaN
D    NaN
E    4.0
F    NaN
dtype: float64
'''

#單個Series運算
print((series1*2).tolist())    #列印：[10, 12, 14, 16]
print(series1[series1>6].tolist())    #列印：[7, 8]
print(np.square(series1).tolist())    #列印：[25, 36, 49, 64]