如何循环两个数据帧的列，group by key并执行计算

import pandas as pd

df1 = pd.DataFrame({'key': ['A', 'B', 'C', 'A', 'B', 'C'],
                    'value1': [1, 2, 3, 4, 5, 6]})
df2 = pd.DataFrame({'key': ['A', 'B', 'C', 'A', 'B', 'C'],
                    'value2': [7, 8, 9, 10, 11, 12]})

merged_df = pd.merge(df1, df2, on='key')

grouped_df = merged_df.groupby('key')

result = grouped_df.mean()

import pandas as pd

df1 = pd.DataFrame({'key': ['A', 'B', 'C', 'A', 'B', 'C'],
                    'value1': [1, 2, 3, 4, 5, 6]})
df2 = pd.DataFrame({'key': ['A', 'B', 'C', 'A', 'B', 'C'],
                    'value2': [7, 8, 9, 10, 11, 12]})

merged_df = pd.merge(df1, df2, on='key')
grouped_df = merged_df.groupby('key')
result = grouped_df.mean()

print(result)