从多索引数据帧中删除标头

import pandas as pd

data = {'Index1': [1, 2, 3, 4],
        'Index2': ['A', 'B', 'C', 'D'],
        'Value': [10, 20, 30, 40]}
df = pd.DataFrame(data)
df.set_index(['Index1', 'Index2'], inplace=True)

df.columns = df.columns.droplevel()