What is the clock on?
The clock is on the shelf.
    src        edge_attr  dst
0     0  to the right of   27
1     0   to the left of   12
2     1               on   15
3     1   to the left of   23
4     1   to the left of   16
..  ...              ...  ...
80   28   to the left of   16
81   28   to the left of   15
82   28   to the left of    6
83   28   to the left of    4
84   28   to the left of    1

[85 rows x 3 columns]