What is on the wall?
The pipes are on the wall.
     src        edge_attr  dst
0      0   to the left of   20
1      0  to the right of   11
2      0   to the left of   23
3      0   to the left of   15
4      0  to the right of    4
..   ...              ...  ...
191   27   to the left of    2
192   27   to the left of   12
193   27  to the right of   22
194   27  to the right of   14
195   27  to the right of   17

[196 rows x 3 columns]