concat 2 dataframe with conditions

Question

i have 2 dataframe I have to concatenate them by checking two conditions

they must have the same id and id1

first dataframe

index     id     id1    name       sexe      age
0         30     AA     momo        M         21
1         31     AA     soso        M         25
2         32     AA     momo        M         18
3         30     BB     LOLO        M         20
4         31     BB     toto        F         20

second dataframe

index     id     id1    note      
0         30     AA      18
1         31     AA      20
2         32     AA      11
3         30     BB       0
4         31    BB       0

Ihave to check if they have the same id1 and id

final dataframe

index     id     id1    name       sexe      age      note
0         30     AA     momo        M         21       18
1         31     AA     soso        M         25       20 
2         32     AA     momo        M         18       11
3         30     BB     LOLO        M         20        0
4         31     BB     toto        F         20        0

id is not unique how can i do that ,i find a duplication problem if i convert id1 to index