python编程求解答哦！下面是我的程序，现实错误如图所示。求解惑~

import pandas as pdimport numpy as npimport mathdf=pd.read_excel('波动率数据.xlsx')jz=df["净值"]xh=df["序号"]product=1i=1j=0k=0result1=0for i in jz: product*=iaveragelogproduct=np.log(pro