I tried to create a graphml file using python and igraph library. I can construct igraph\'s graph object and wrote it to a file using:
g.write_graphml(\"mygraph.
I think problem should come from Unicode invalid bytes sequence problem but without your file I can only guess.
I think you may load string from non-Unicode encoding file and use it directly without convert to Unicode encoding. Please try convert these strings to Unicode by see this post.
a busy cat http://goo.gl/CFGYf