Are the street lights on top of the post?
Yes, the street lights are on top of the post.
   src        edge_attr  dst
0    1  to the right of    6
1    1   to the left of    7
2    2   to the left of    3
3    3        on top of    0
4    3  to the right of    2
5    3               on    0
6    6   to the left of    1
7    7  to the right of    1