import pandas as pd
import numpy as np
t=pd.read_csv('C:/Users/Administrator/Desktop/Car_sales.csv',sep='\t')#加载读取csv汽车销售数据文件
#(1)查询各类汽车厂商的销售数量，以及每个厂商销售最好的汽车型号
df=t.set_index(keys=['Manufacturer','Sales_in_thousands'],append=False,drop=True)
以上为我的代码，csv文件导入到python中的形式如下：
Manufacturer,Model,Sales_in_thousands,__year_resale_value,Vehicle_type,Price_in_thousands,Engine_size,Horsepower,Wheelbase,Width,Length,Curb_weight,Fuel_capacity,Fuel_efficiency,Latest_Launch,Power_perf_factor
0 Acura,Integra,16.919,16.36,Passenger,21.5,1.8,.
1 Acura,TL,39.384,19.875,Passenger,28.4,3.2,225,.
2 Acura,CL,14.114,18.225,Passenger,,3.2,225,106.
3 Acura,RL,8.588,29.725,Passenger,42,3.5,210,114.
4 Audi,A4,20.397,22.255,Passenger,23.99,1.8,150,.
.. ..
152 Volvo,V40,3.545,,Passenger,24.4,1.9,160,100.5,..
153 Volvo,S70,15.245,,Passenger,27.5,2.4,168,104.9..
154 Volvo,V70,17.531,,Passenger,28.8,2.4,168,104.9..
155 Volvo,C70,3.493,,Passenger,45.5,2.3,236,104.9,..
156 Volvo,S80,18.969,,Passenger,36,2.9,201,109.9,7..
[157 rows x 1 columns]
结果报错KeyError: "None of ['Manufacturer', 'Sales_in_thousands'] are in the columns"
明明没有输错，为什么找不到这两个呢
