Python Pandas-如何添加总行来求某些列的和,并取其他列的平均值

我有以下代码可以按预期工作

df['FPYear'] = df['First_Purchase_Date'].dt.year
# Table2 = df.loc[df.Date.between('2018-11-22','2018-11-30')].groupby(df['FPYear'])[['New Customer', 'Existing Customer', 'revenue']].sum() #with date filters for table
Table2 = df.loc[df.Date.between('2018-11-22','2018-11-30') & (df['Region'] == 'Canada')].groupby(df['FPYear'])[['New Customer', 'Existing Customer', 'revenue']].sum() #with date filters for table
Table2['TotalCusts'] = Table2['New Customer'] + Table2['Existing Customer']
Table2['Cohort Size'] = Table['New Customer']

Table2['Repeat Rate'] = Table2['Existing Customer']/Table2['TotalCusts']
Table2['NewCust Rate'] = Table2['New Customer']/Table2['TotalCusts']
Table2['PCT of Total Yr'] = Table2['TotalCusts']/Table['New Customer']
Table2.loc['Total'] = Table2.sum(axis = 0)

print(Table2)

我可以用以下代码添加总行 Table2.loc['Total'] = Table2.sum(axis = 0) 不过,它也将total应用于“Repeat Rat”和“NewCust Rate”列,但我希望能够取total行中这些行的平均值。我怎样才能修改总行数,使之取平均值。