Is the signal light to the right of a train?
No, the signal light is to the right of a ladder.
     src        edge_attr  dst
0      0   to the left of   19
1      0   to the left of    8
2      1  to the right of    3
3      2   to the left of   25
4      2   to the left of   24
..   ...              ...  ...
117   26  to the right of    7
118   26   to the left of   22
119   26  to the right of   14
120   26  to the right of   24
121   27  to the right of   13

[122 rows x 3 columns]