Are there any fences or flags?
Yes, there is a flag.
     src        edge_attr  dst
0      0   to the left of   33
1      0  to the right of   16
2      0  to the right of   20
3      0  to the right of   24
4      0   to the left of   22
..   ...              ...  ...
132   33               on    9
133   33   to the left of   17
134   33  to the right of   22
135   33   to the left of   23
136   33  to the right of    0

[137 rows x 3 columns]