Hi, I am wondering: is it possible to generate a vertex variable name from a string. Let me explain: I need to read a set of vertices from a csv file, and a set of arcs from another file. My vertices have names of the form XYZ, and my arcs then indicate whether there is a connection between XYZ and, say, ABC. Of course, I could define a property "name", assign it to the vertex, then find the indices of the origin and end vertices when I browsing my connection file. But I am wondering.. From the examples, I would like to do something like v1 = g.add_vertex() v2 = g.add_vertex() e = g.add_edge(v1, v2) but where v1, v2, etc., would be replaced by vertexName[i] (in a loop). Probably it is my incompetence with python, but I don't seem to be able to do that. A call to for i in range(1, len(vertexName)): vertexName[i] = g.add_vertex() does not give an error. But when I try to assign an edge using the "same" method, for i in range(1, len(listVertices)): e = g.add_edge(origVertex[i], destVertex[i]) I get Traceback (innermost last): File "<stdin>", line 1, in <module> File "import_graph.py", line 59, in <module> e = g.add_edge(origVertex[i], destVertex[i]) File "/usr/local/lib/python2.7/dist-packages/graph_tool/__init__.py", line 1109, in add_edge e = libcore.add_edge(weakref.ref(self), source, target) TypeError: No registered converter was able to extract a C++ reference to type graph_tool::PythonVertex from this Python object of type str I am guessing that, if at all possible, then some typecasting is needed.. So, is it possible and if so, how? Thanks! -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/... Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.