[igraph] visualizing vertex error

[Ahmed Abdeen Hamed]

Hello,

I need to change the size of the vertex based on the PageRank value. I wrote the following code:

pr =  g.pagerank()

visual_style["vertex_size"] = [float(15 *pr[v.index]) for v in g.vs]

Here is the error:

Any idea what the error is about?

Thanks very much,

-Ahmed