Are there any lamps?
Yes, there is a lamp.
     src        edge_attr  dst
0      0  to the right of   21
1      0  to the right of    5
2      0  to the right of   12
3      0  to the right of   14
4      0   to the left of   18
..   ...              ...  ...
148   33   to the left of   20
149   34  to the right of   29
150   34  to the right of   35
151   35   to the left of   34
152   35               on   29

[153 rows x 3 columns]