Are there any trains that are blue?
Yes, there is a blue train.
    src        edge_attr  dst
0     1   to the left of    7
1     1  to the right of   19
2     1  to the right of    9
3     2  to the right of    4
4     2   to the left of    3
..  ...              ...  ...
91   25  to the right of   11
92   25  to the right of    5
93   26  to the right of   27
94   26   to the left of   11
95   27   to the left of   26

[96 rows x 3 columns]