Which side are the books on?
The books are on the left of the image.
    src        edge_attr  dst
0     0  to the right of    5
1     0  to the right of    2
2     1  to the right of    5
3     1  to the right of    2
4     2  to the right of   18
..  ...              ...  ...
59   18   to the left of   10
60   18   to the left of    9
61   19   to the left of    5
62   19   to the left of    2
63   20   to the left of    7

[64 rows x 3 columns]