What is the vehicle that is pulling a cart?
The vehicle is a train.
    src        edge_attr  dst
0     0   to the left of    4
1     0  to the right of    3
2     1  to the right of    6
3     1  to the right of    5
4     1  to the right of    2
..  ...              ...  ...
89   25   to the left of   18
90   25   to the left of   23
91   26   to the left of    4
92   26  to the right of   18
93   26  to the right of    5

[94 rows x 3 columns]