How to merge 2 adjacent edges into one edge in NetworkX

Question

e.g. I have one graph with 3 nodes: a,b,c and 2 edges (a,b), (b,c). Now I'd like remove node b and merge edges (a,b),(b,c) into one edge (a,c), is there any api in networkx for this kind of graph manipulation? Thanks

Answer 1

You can use networkx.contracted_nodes to generate a new graph with b merged into a:

G = nx.from_edgelist([('a', 'b'), ('b', 'c')])

H = nx.contracted_nodes(G, 'a', 'b', self_loops=False)

Or using contracted_edge:

H = nx.contracted_edge(G, ('a', 'b'), self_loops=False)

NB. this returns a new graph, if you want to update in place, use copy=False.

Before:

After: