igraph: how to use add_edges when there are attributes?

Question

What if I need to create a graph in igraph and add a bunch of edges, but the edges have associated attributes? It looks like .add_edges can only take a list of edges without attributes, so I've been adding them one by one with .add_edge

Answer 1

graph.add_edge('A','B',weight = 20)

Here A and B are names of nodes

Answer 2

You can assign the attributes later; e.g.:

graph.es["weight"] = range(g.ecount())

This will assign weights to all the edges at once. If you want to assign attributes to only a subset of the edges, index or slice the edge sequence (g.es) in however you want:

graph.es[10:20]["weight"] = range(10)