Question

I’m using a dictionary to represent a graph in my Python program. I’m using the keys of the dictionary to represent vertices and the values to represent the adjacent nodes of each vertex. The dictionary currently looks like this:

{  
   'v1' : ['v2','v3'],
   'v2' : ['v1'],
   'v3' : ['v1','v4'],
   'v4' : ['v3']
    // And so on. 
}

Is there a straightforward way to create a new igraph object from this dictionary? If there’s no easy way, what’s the next-best option?

Answer 1

Well, according to the docs, it seems that igraph expects vertices encoded as integers. So you need to specify a mapping from your vertices to integers and then you could actually proceed for example like this:

G= {'v1': ['v2', 'v3'], 'v2': ['v1'], 'v3': ['v1', 'v4'], 'v4': ['v3']}
mvi= {'v1': 1, 'v2': 2, 'v3': 3, 'v4': 4}
graph= igraph.Graph(edges= [(mvi[v], mvi[a]) for v in G.keys() for a in G[v]])