Having problems converting networkx graph to igraph graph

Question

I wish to take a graph, G, created in networkx and convert it to an igraph, g, for use with the leidenalg community detection package. This used to work for me, but now I'm encountering problems.

Working with Python 3 in a Jupyter notebook on a Mac running Catalina OSX. Python-igraph is version 0.7.1.post7.

import numpy as np
import networkx as nx
import igraph as ig
A=np.matrix([[0,7,7,0,0],[7,0,6,0,0],[7,6,0,2,1],[0,0,2,0,4],[0,0,1,4,0]])
G=nx.from_numpy_matrix(A)
nx.write_graphml(G,'graph.graphml')
g = ig.read('graph.graphml',format="graphml")

The error message says "module 'igraph' has no attribute 'read'" Replacing the last line with

g=ig.Read_GraphML('graph.graphml')

does not eliminate the error message.

For some reason, this does work in Spyder with Python 3.7

Answer 1

My guess is that you have installed the wrong package in your virtualenv.

There are 2 libraries:

1. igraph (installed with pip install igraph )
2. python-igraph (installed with brew install igraph && pip install python-igraph ). This is the one which contains the read method.

Both can be referred to as import igraph .

Try to run pip freeze to check if in your environment you have installed the correct package.