Is the knife on the left side?
No, the knife is on the right of the image.
   src        edge_attr  dst
0    0   to the left of    2
1    2  to the right of    0
2    2  to the right of    3
3    2   to the left of    4
4    3   to the left of    2
5    4  to the right of    2
6    5   to the left of    8
7    7   to the left of    8
8    8  to the right of    5
9    8  to the right of    7