浅谈Pandas:Series和DataFrame间的算术元素

import numpy as np
import pandas as pd
from pandas import Series,DataFrame

s1 = Series([1,3,5,7],index=['a','b','c','d'])
s2 = Series([2,4,6,8],index=['a','b','c','e'])

s1+s2
1
a  3.0
b  7.0
c 11.0
d  NaN
e  NaN
dtype: float64

data1 = {'水果':['苹果','梨','草莓'],
  '数量':[3,2,5],
  '价格':[10,9,8]}
data2 = {'数量':[3,2,5,6],
  '价格':[10,9,8,7]}
df1 = DataFrame(data1)
df2 = DataFrame(data2)

print(df1*df2)

  价格 数量 水果
0 100.0 9.0 NaN
1 81.0 4.0 NaN
2 64.0 25.0 NaN
3 NaN NaN NaN

print(df2+df2.iloc[0]) # 将第0行加到所有行上

 价格 数量
0 20 6
1 19 5
2 18 8
3 17 9

print(df2.sub(df2.iloc[:,0],axis=0))

 价格 数量
0 0 -7
1 0 -7
2 0 -3
3 0 -1

s = Series([1,1,1],index=['数量','价格','重量'])
print(df2+s)

 价格 数量 重量
0 11 4 NaN
1 10 3 NaN
2 9 6 NaN
3 8 7 NaN