如何使用pandas创建多个索引行

import pandas as pd

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

index = pd.MultiIndex.from_tuples([('Group1', 'Index1'), ('Group1', 'Index2'), ('Group2', 'Index1'), ('Group2', 'Index2')])
df.index = index

print(df)

                A  B   C
Group1 Index1  1  5   9
       Index2  2  6  10
Group2 Index1  3  7  11
       Index2  4  8  12