The standard str is unicode now... 2to3 . --fix unicode -wpn Ref: https://docs.python.org/3/whatsnew/3.0.html
altgraph is a fork of graphlib: a graph (network) package for constructing graphs, BFS and DFS traversals, topological sort, shortest paths, etc. with graphviz output. altgraph includes some additional usage of Python 2.6+ features and enhancements related to modulegraph and macholib.