在Pandas中将基于多个条件的值替换为groupby mean

import pandas as pd

# 创建一个示例数据集
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)

# 将基于多个条件的值替换为groupby mean
df['C'] = df.groupby(['A', 'B'])['C'].transform('mean')

print(df)

     A    B    C   D
0  foo  one  4.5  10
1  bar  one  6.0  20
2  foo  two  5.0  30
3  bar  two  4.0  40
4  foo  two  5.0  50
5  bar  one  6.0  60
6  foo  two  5.0  70
7  foo  one  4.5  80