Question

我有2个数据框df1和df2，我想根据它们的列'C'来加入

import pandas

df1 = pandas.DataFrame(data=[[1,0,2,4],[2,3,1,3]],columns=['A','B','C','D'])
df2 = pandas.DataFrame(data=[[2,2,2,4],[3,4,1,3]],columns=['A','F','C','D'])

    df1
   A  B  C  D
0  1  0  2  4
1  2  3  1  3

   df2
   A  F  C  D
0  2  2  2  4
1  3  4  1  3

# Merge the dataframes
dataframe_matched = df1.join(
    other=df2.set_index('C'),
    on='C',
    how="inner",
    lsuffix="_left",
    rsuffix="_right",
    sort=True,
)


dataframe_matched
   A_left  B  C  D_left  A_right  F  D_right
1       2  3  1       3        3  4        3
0       1  0  2       4        2  2        4

列D_left和D_right相同。有没有一种简单的方法可以将原始名称保留为1？

dataframe_matched
   A_left  B  C       D  A_right  F
1       2  3  1       3        3  4
0       1  0  2       4        2  2

Answer 1

您可以进行drop_duplicates

df1.merge(df2,on='C').T.drop_duplicates().T
Out[288]: 
   A_x  B  C  D_x  A_y  F
0    1  0  2    4    2  2
1    2  3  1    3    3  4

更新

pd.concat([df1.set_index('C'),df2.set_index('C')],1,keys=['right','left']).\
   T.reset_index(level=1).\
     drop_duplicates().set_index('level_1',append=True).T
Out[337]: 
        right       left   
level_1     A  B  D    A  F
C                          
2           1  0  4    2  2
1           2  3  3    3  4

大熊猫加入删除列如果相同

1 个答案: