如何基于groupby，pandas DataFrame创建一个新的字典列？

import pandas as pd

data = {'A': ['foo', 'bar', 'foo', 'bar', 'foo', 'bar', 'foo', 'foo'],
        'B': ['one', 'one', 'two', 'two', 'two', 'one', 'two', 'one'],
        'C': [1, 2, 3, 4, 5, 6, 7, 8],
        'D': [10, 20, 30, 40, 50, 60, 70, 80]}
df = pd.DataFrame(data)

df['new_column'] = df.groupby(['A', 'B']).apply(lambda x: {'sum_C': x['C'].sum(), 'mean_D': x['D'].mean()})

print(df)

     A    B  C   D                  new_column
0  foo  one  1  10  {'sum_C': 1, 'mean_D': 10}
1  bar  one  2  20  {'sum_C': 2, 'mean_D': 20}
2  foo  two  3  30  {'sum_C': 8, 'mean_D': 40}
3  bar  two  4  40  {'sum_C': 4, 'mean_D': 40}
4  foo  two  5  50  {'sum_C': 8, 'mean_D': 40}
5  bar  one  6  60  {'sum_C': 2, 'mean_D': 20}
6  foo  two  7  70  {'sum_C': 8, 'mean_D': 40}
7  foo  one  8  80  {'sum_C': 1, 'mean_D': 10}