two column of 1 data frame and other two column of 2nd data frame now extract the value use by these two data frame
df1[["source", "Tar"] df2["id", "me"]
source Tar id me
cd1 ef2 60_2 ac4
cd1 hi1 50_6 xg3
zx2 an2
cd1 60_2
zx2 50_6
Output should be
df1["source" , "Tar"]
source Tar
cd1 ef2
cd1 hi1
zx2 an2
cd1 ac4
zx2 xg3