Is the train to the right or to the left of the fence?
The train is to the left of the fence.
     src        edge_attr  dst
0      0           behind    1
1      0   to the left of    6
2      0           behind   11
3      0  to the right of    8
4      1      in front of   21
..   ...              ...  ...
138   21  to the right of   20
139   21  to the right of    1
140   21   to the left of    6
141   21  to the right of   18
142   21  to the right of   19

[143 rows x 3 columns]