组多索引Pandas数据框

Answer 1

是的，使用level参数。看看here。示例：

In [26]: s

first  second  third
bar    doo     one      0.404705
               two      0.577046
baz    bee     one     -1.715002
               two     -1.039268
foo    bop     one     -0.370647
               two     -1.157892
qux    bop     one     -1.344312
               two      0.844885
dtype: float64

In [27]: s.groupby(level=['first','second']).sum()

first  second
bar    doo       0.981751
baz    bee      -2.754270
foo    bop      -1.528539
qux    bop      -0.499427
dtype: float64