如何使用其中之一的索引合并数据帧？

Question

I have two data frames (A and B) as following:

*The types are:

<class 'pandas.core.frame.DataFrame'> ---> A

<class 'pandas.core.frame.DataFrame'> ---> B

A:

         target
145        1
557        1
240        1
893        1
1518       0
1145       0

B:

      RF  LR  NB  DT  SVM  Knn  SUM
0     1   0   0   1    1    1    4
1     1   1   1   1    0    1    5
2     1   1   1   1    1    1    6
3     1   1   1   1    1    1    6
4     1   0   0   1    0    0    2
5     1   1   1   0    1    1    5

I need one data frame that will include both.

How can I merge them together (by columns) by using the indexing of A (and ignore the indexing of B) ?

Answer 1

IIUC, you can drop the index from A , join or concat the two frames, and reset the index to be A 's index:

A.reset_index(drop=True).join(B).set_index(A.index)
# or
pd.concat((A.reset_index(drop=True), B),axis=1).set_index(A.index)

      target  RF  LR  NB  DT  SVM  Knn  SUM
145        1   1   0   0   1    1    1    4
557        1   1   1   1   1    0    1    5
240        1   1   1   1   1    1    1    6
893        1   1   1   1   1    1    1    6
1518       0   1   0   0   1    0    0    2
1145       0   1   1   1   0    1    1    5