Is the color of the train different than that of the train car?
Yes, the train car is blue and the train is white.
   src        edge_attr  dst
0    0   to the left of    4
1    0   to the left of    1
2    0   to the left of    3
3    1  to the right of    0
4    2  on the front of    1
5    3  to the right of    0
6    4  to the right of    0