What is on the shelf?
The bicycle is on the shelf.
     src       edge_attr  dst
0      0     in front of    6
1      0  to the left of    2
2      0  to the left of    7
3      0  to the left of   16
4      0  to the left of   15
..   ...             ...  ...
114   17              on   12
115   18  to the left of   16
116   18  to the left of   13
117   18  to the left of    7
118   18  to the left of   15

[119 rows x 3 columns]