我有orders_df: Symbol Order Shares
Date
2011-01-10 AAPL BUY 1500
2011-01-13 AAPL SELL 1500
2011-01-13 IBM BUY 4000
2011-01-26 GOOG BUY 1000
2011-02-02 XOM SELL 4000
2011-02-10 XOM BUY 4000
我用下面的代码在一个数据帧,以创建新列: # data is a dataframe object
data.loc[:,'test'] = 5
它带有以下警告: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_ind