Difference of 2 files in Pandas

Question

I have 2 csv files. First File :

1
2
3
4

Second file

1,abc
2,dfg
3,hgj
4,fgh
5,rts

How can i compare these 2 files and return matching rows from second file (based on column 1). Expected results below.

1,abc
2,dfg
3,hgj
4,fgh