Merge two dataframes by different indexes-CodePudding

I am trying to merge two dataframes based on the Date column but in df1 the data column is titled Index while the other is called Date.

`df1`

Index	SMB	HML	RF
2018	2	3	4
2019	4	4	5
2020	4	5	2

`df2`

Date	ABC	DEF	GHI
2018	22	38	49
2019	41	42	59
2020	41	54	29

I have tried to set the index in DF1 but i keep getting the error message : "None of ['Index'] are in the columns"

This is the code I have tried:

df1 = df1.set_index('Index').T.set_index('Date').T

df1 data was imported if that changes anything. I would like to eventually merge the two dataframes so it looks something like this:

`df3`

Date	ABC	DEF	GHI	SMB	HML	RF
2018	22	38	49	2	3	4
2019	41	42	59	4	4	5
2020	41	54	29	4	5	2

CodePudding user response：

df3 = df2.merge(df1, right_on='Index', left_on='Date').drop('Index', axis=1)

Output:

>>> df3
   Date  ABC  DEF  GHI  SMB  HML  RF
0  2018   22   38   49    2    3   4
1  2019   41   42   59    4    4   5
2  2020   41   54   29    4    5   2