Which side of the picture is the lamp on?
The lamp is on the left of the image.
   src        edge_attr  dst
0    0   to the left of   11
1    0   to the left of    3
2    0   to the left of   12
3    3  to the right of    0
4    9  to the right of   11
5   11   to the left of    9
6   11  to the right of    0
7   12  to the right of    0