could not import graph_tool in Python
I used "port install py-graph-tool" to install graph-tool on Mac, but could not import graph_tool in Python. below is what I got in the terminal.
---> Cleaning py27-graph-tool
---> Fetching archive for py-graph-tool
---> Attempting to fetch py-graph-tool-2.19_0.darwin_14.noarch.tbz2 from https://packages.macports.org/py-graph-tool
---> Attempting to fetch py-graph-tool-2.19_0.darwin_14.noarch.tbz2 from http://sea.us.packages.macports.org/macports/packages/py-graph-tool
---> Attempting to fetch py-graph-tool-2.19_0.darwin_14.noarch.tbz2 from http://lil.fr.packages.macports.org/py-graph-tool
---> Fetching distfiles for py-graph-tool
---> Verifying checksums for py-graph-tool
---> Extracting py-graph-tool
---> Configuring py-graph-tool
---> Building py-graph-tool
---> Staging py-graph-tool into destroot
---> Installing py-graph-tool @2.19_0
---> Activating py-graph-tool @2.19_0
---> Cleaning py-graph-tool
---> Updating database of binaries
---> Scanning binaries for linking errors
---> No broken files found.