如何在dataframe中使用pandas创建具有不同子列标题的自定义多索引

import pandas as pd

data = {'A': [1, 2, 3, 4, 5],
        'B': [6, 7, 8, 9, 10],
        'C': [11, 12, 13, 14, 15],
        'D': [16, 17, 18, 19, 20]}
df = pd.DataFrame(data)

columns = pd.MultiIndex.from_tuples([('Group 1', 'Column 1'), ('Group 1', 'Column 2'), ('Group 2', 'Column 3'), ('Group 2', 'Column 4')])
df.columns = columns

print(df)

  Group 1       Group 2      
 Column 1 Column 2 Column 3 Column 4
0        1        6       11       16
1        2        7       12       17
2        3        8       13       18
3        4        9       14       19
4        5       10       15       20