[igraph] Adding edges by ID

[Ehecatl Antonio del R�o Chanona]

Hello everyone,

I am trying to add edges to a graph (through IDs), however this does not seem to work. I know how to add them by using the vertex number, however being able to add them by their ID would really make things much easier for me.

I have:

>>>node_list = ['v1','v2',...] (a list of IDs)

I create the graph:

>>>A = Graph(len(nodes_list))

Add the IDs to the graph:

>>>for vertex in range(len(nodes_list)):

>>>    A.vs[vertex]["id"]= nodes_list[vertex]

When I actually print these vertices “>>> print A.vs[vertex]” I get

>>>igraph.Vertex(<igraph.Graph object at 0xaa6a0ac>,0,{'id': 'v1'})

>>>igraph.Vertex(<igraph.Graph object at 0xaa6a0ac>,1,{'id': 'v2'})

...

and so on

Then I create my list of edges:

>>>Edges_list = [('v1', 'v2'), ('v2', 'v3')...]

When I try to add these edges to the graph

>>>A.add_edges(Edges_list)

I get the error:

ValueError: no such vertex: 'v1'

Where 'v1' would be any vertex in the position of the first vertex in the first edge in the list Edges_list.

I have looked through the documentation, but I can't find what I am doing wrong.

Could you give me any suggestions please?

Many thanks

Antonio