Which side is the shelf on?
The shelf is on the right of the image.
    src       edge_attr  dst
0     0  to the left of   13
1     0  to the left of   18
2     0  to the left of   17
3     0  to the left of    2
4     0  to the left of    1
..  ...             ...  ...
82   20  to the left of   13
83   20  to the left of    4
84   20  to the left of    3
85   20  to the left of    2
86   20  to the left of   17

[87 rows x 3 columns]