如何从Multi-Index中获取列？

import pandas as pd

# 创建一个具有Multi-Index的DataFrame
data = {
    ('A', 'X'): [1, 2, 3],
    ('A', 'Y'): [4, 5, 6],
    ('B', 'X'): [7, 8, 9],
    ('B', 'Y'): [10, 11, 12]
}
df = pd.DataFrame(data, index=['row1', 'row2', 'row3'])

# 使用loc方法获取列
column_A = df.loc[:, ('A', 'X')]
column_B = df.loc[:, ('B', 'Y')]

print(column_A)
print(column_B)

row1    1
row2    2
row3    3
Name: (A, X), dtype: int64
row1    10
row2    11
row3    12
Name: (B, Y), dtype: int64