import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rc
import matplotlib

rc('font', family='AppleGothic')
plt.rcParams['axes.unicode_minus'] = False

data = np.random.randint(1,10, size=4)
data

array([2, 9, 5, 7])

data = np.random.randint(30,101, size=(4,6) )
data

array([[94, 42, 91, 67, 54, 94],
       [87, 30, 83, 31, 92, 65],
       [83, 43, 99, 43, 37, 59],
       [82, 88, 48, 48, 59, 70]])

df = pd.DataFrame( data )
df

df['년도'] = [2018,2018,2019,2019]
df['반'] = ['1반','2반','1반','2반']
df

df.set_index(['년도','반'])

df

df.index = pd.MultiIndex.from_product([[2018,2019],['1반','2반']],
                           names=['년도','반'])
df

df.index

MultiIndex([(2018, '1반'),
            (2018, '2반'),
            (2019, '1반'),
            (2019, '2반')],
           names=['년도', '반'])

df.index.levels[1]

Index(['1반', '2반'], dtype='object', name='반')

df.index.get_level_values(0)

Int64Index([2018, 2018, 2019, 2019], dtype='int64', name='년도')

df.index.get_level_values(1)

Index(['1반', '2반', '1반', '2반'], dtype='object', name='반')

df.drop(columns=['년도','반'],inplace=True)
df

df.reset_index() #인덱스를 칼럼으로 보냄

df

df.loc[2018]

df.columns = pd.MultiIndex.from_product([['홍길동','이순신','임꺽정'],['국어','영어']],)
df

df.columns.levels[0]

Index(['이순신', '임꺽정', '홍길동'], dtype='object')

df.columns.levels[1]

Index(['국어', '영어'], dtype='object')

df['이순신']

review
- pd.MultiIndex.from_product()