What is this, a train or a bus?
This is a train.
    src        edge_attr  dst
0     1  to the right of    9
1     1  to the right of    8
2     1  to the right of    2
3     1   to the left of    6
4     2   to the left of    1
5     2   to the left of    9
6     2  to the right of    8
7     4  to the right of    7
8     6  to the right of    1
9     7   to the left of    4
10    8   to the left of    2
11    8   to the left of    1
12    8   to the left of    9
13    9   to the left of    1
14    9  to the right of    8
15    9  to the right of    2
16   10               in    5
17   12               on   11