Using GraphMatcher to find a subgraph.

findsubgraph.py

"""
Example demonstrating how to modify the GraphMatcher class so that 
subgraph_is_isomorphic() will determine whether G2 is a subgraph (with
an identity isomorphism).

"""

import networkx as nx

G = nx.karate_club_graph()

# Grab a subgraph.
subG_good = G.subgraph(range(10))

# Make an isomorphic subgraph.
subG_bad = nx.relabel_nodes(subG_good, dict(zip(range(10), 'abcdefghij')))

class GraphMatcher(nx.algorithms.isomorphism.GraphMatcher):
    def semantic_feasibility(self, G1_node, G2_node):
        return G1_node == G2_node

gm = GraphMatcher(G, subG_good)
print gm.subgraph_is_isomorphic() # True

gm = GraphMatcher(G, subG_bad)
print gm.subgraph_is_isomorphic() # False