NetworkX: Subgraph Isomorphism by edge and node attributes

Question

Suppose I have 2 graphs A and B and I want to know if A is a subgraph of B. The nodes contain attributes, say, 'size' and 'material'.

When I run:

GM = networkx.algorithms.isomorphism.GraphMatcher(B,A)
print networkx.algorithms.isomorphism.subgraph_is_isomorphic()

This only matches graph by edges only and not by edges and attribute.

Any clue on how check attributes?

Also, suppose B contains 2 connected graphs of A.

When I run:

GM.mapping

This will output only 1 of the subgraphs of A. Any idea on how to output every subgraph?

Answer 1

I've solved this by using:

print GM = iso.GraphMatcher(B,A,node_match=iso.categorical_node_match(['material', 'size'],['metal',1]))

What I didn't know before is that ['metal',1] is just a default and not a hard match.

Answer 2

You can iterate over all possible subgraphs in the following way

GM = networkx.algorithms.isomorphism.GraphMatcher(B,A)
for subgraph in GM.subgraph_isomorphisms_iter():
    print subgraph

subgraph in this example is a dictionary that maps nodes of B to nodes of A.

For the question of attribute matching, drum's suggestion has worked for me. Additional attribute matching actually speeds up things significantly for large graphs.