从行对构建多索引数据帧

import pandas as pd

# 创建一个多索引数据帧
arrays = [
    ['A', 'A', 'B', 'B'],
    ['one', 'two', 'one', 'two']
]
index = pd.MultiIndex.from_arrays(arrays, names=('first', 'second'))
df = pd.DataFrame({'value': [10, 20, 30, 40]}, index=index)

print(df)

              value
first second       
A     one        10
      two        20
B     one        30
      two        40

# 选择特定层级的数据
print(df.loc[pd.IndexSlice['A', 'one'], :])

              value
first second       
A     one        10

# 对多索引数据帧进行排序
df_sorted = df.sort_index(level='first')
print(df_sorted)

              value
first second       
A     one        10
      two        20
B     one        30
      two        40