Who is in the classroom?
The man is in the classroom.
    src        edge_attr  dst
0     0  to the right of    3
1     0  to the right of    7
2     0  to the right of   15
3     0  to the right of   20
4     1   to the left of   10
..  ...              ...  ...
73   20   to the left of    0
74   20   to the left of    7
75   20   to the left of    9
76   20   to the left of   17
77   20   to the left of   15

[78 rows x 3 columns]