pandas groupby + apply的快速替代品？

import pandas as pd

# 创建一个DataFrame
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)

# 使用groupby + agg进行聚合计算
result = df.groupby(['A', 'B']).agg({'C': 'sum', 'D': 'mean'})
print(result)

         C     D
A   B          
bar one   20  40.0
    two    4  40.0
foo one    9  50.0
    two   10  70.0