What is on the gate made of iron?
The lock is on the gate.
    src        edge_attr  dst
0     0   to the left of    7
1     0   to the left of   17
2     0  to the right of   19
3     0   to the left of   18
4     1   to the left of    7
..  ...              ...  ...
72   19   to the left of   16
73   19   to the left of    4
74   19   to the left of   11
75   19   to the left of   18
76   19   to the left of    8

[77 rows x 3 columns]