Filtering a subgraph in graph-tool

You are right. You have to use GraphView. In the following example a induced subgraph with vertices 0, 1, 3 are created from a complete graph with 5 vertices

from graph_tool import GraphView, generation

g = generation.complete_graph(5)

# select some vertices
vfilt = g.new_vertex_property('bool');
vfilt[0] = True
vfilt[1] = True
vfilt[3] = True

sub = GraphView(g, vfilt)

print [(g.vertex_index[e.source()], g.vertex_index[e.target()])
           for e in sub.edges()]

Output

[(0, 1), (0, 3), (1, 3)]