Are both the post and the fence made of the same material?
No, the post is made of concrete and the fence is made of metal.
    src        edge_attr  dst
0     1  to the right of   14
1     1  to the right of   12
2     1  to the right of    2
3     1  to the right of    9
4     2  to the right of    8
5     2   to the left of    1
6     3  to the right of   14
7     5  to the right of   14
8     8   to the left of    2
9     9   to the left of    1
10    9  to the right of   12
11   10               of    6
12   12   to the left of    9
13   12   to the left of    1
14   14   to the left of    1
15   14   to the left of    3
16   14   to the left of    5