📅  最后修改于: 2022-03-11 14:45:55.746000             🧑  作者: Mango
In [11]: df.groupby(['Country', 'Item_Code'])[["Y1961", "Y1962", "Y1963"]].sum()
Out[11]:
Y1961 Y1962 Y1963
Country Item_Code
Afghanistan 15 10 20 30
25 10 20 30
Angola 15 30 40 50
25 30 40 50