What is the number on?
The number is on the sign.
     src        edge_attr  dst
0      0   to the left of   31
1      0   to the left of   28
2      0   to the left of   32
3      0   to the left of   20
4      0   to the left of   12
..   ...              ...  ...
144   32  to the right of    0
145   32  to the right of   22
146   32   to the left of   25
147   32  to the right of   31
148   32  to the right of   28

[149 rows x 3 columns]