pd.merge 2つのdataframeをマージ

import pandas as pd
>>> df1=pd.DataFrame({
'a':[0,0,0,0,1,1,1,1],
'b':[0,0,1,1,0,0,1,1] ,
'c':[1,2,3,4,5,6,7,8],
'd':['h','i','j','k','l','m','n','o']
})
>>> df2=pd.DataFrame({
'a':[0,0,1,1],
'b':[0,1,0,1] ,
'e':[4,5,6,7],
'f':['x','y','z','z']
})
>>> df1
   a  b  c  d
0  0  0  1  h
1  0  0  2  i
2  0  1  3  j
3  0  1  4  k
4  1  0  5  l
5  1  0  6  m
6  1  1  7  n
7  1  1  8  o
>>> df2
   a  b  e  f
0  0  0  4  x
1  0  1  5  y
2  1  0  6  z
3  1  1  7  z
>>> df = df1.merge(df2,on=['a','b'])
>>> df
   a  b  c  d  e  f
0  0  0  1  h  4  x
1  0  0  2  i  4  x
2  0  1  3  j  5  y
3  0  1  4  k  5  y
4  1  0  5  l  6  z
5  1  0  6  m  6  z
6  1  1  7  n  7  z
7  1  1  8  o  7  z
>>> df_one = df[['a','c','f']]
>>> df_one
   a  c  f
0  0  1  x
1  0  2  x
2  0  3  y
3  0  4  y
4  1  5  z
5  1  6  z
6  1  7  z
7  1  8  z
>>>