Is this a train or a bus?
This is a bus.
    src        edge_attr  dst
0     2   to the left of    4
1     3   to the left of    6
2     3  to the right of    5
3     4  to the right of    2
4     4   to the left of    7
5     4   to the left of    6
6     5   to the left of    3
7     6  to the right of    3
8     6  to the right of    4
9     7               on    0
10    7  to the right of    4