从pandas.DataReader。获取数据时，它返回远程数据错误

Question

代码：

import pandas_datareader.data as web
import datetime

start =datetime.datetime(2010,1,1)
end   =datetime.datetime(2013,1,1)

prices = web.DataReader(['CSV','BP','XOM'],'yahoo',start ,end)['Adj Close']

prices.head()