Here is the first df:
index name
4 a
8 b
10 c
Here is the second df:
index name
4 d
5 d
6 d
7 d
8 e
9 e
10 f
Is there a way to join them as below df?
index name1 name2
4 a d
5 a d
6 a d
7 a d
8 b e
9 b e
10 c f
Basically join two df base on index, then auto fill the gap on name1 base on the first value.