import pandas as pd
df = pd.DataFrame({'A': ['a', 'b', 'a'],
                   'B': ['b', 'a', 'c']})
print(pd.get_dummies(df))

#    A_a  A_b  B_a  B_b  B_c
# 0    1    0    0    1    0
# 1    0    1    1    0    0
# 2    1    0    0    0    1

df = pd.DataFrame({('i','A'): ['a', 'b', 'a'],
                   ('ii','B'): ['b', 'a', 'c']})
ret = pd.get_dummies(df)
print(ret)
print(type(ret.columns[0]))

#    ('i','A')_a  ('i','A')_b  ('ii','B')_a  ('ii','B')_b  ('ii','B')_c
# 0            1            0             0             1             0
# 1            0            1             1             0             0
# 2            1            0             0             0             1
#
# str

#   ('i','A','a') ('i','A','b') ('ii','B','a') ('ii','B','b') ('ii','B','c')
# 0            1             0              0              1              0
# 1            0             1              1              0              0
# 2            1             0              0              0              1

#    i    ii
#    A     B
#    a  b  a  b  c
# 0  1  0  0  1  0
# 1  0  1  1  0  0
# 2  1  0  0  0  1