g.getIndexedKeys on Titan fails

[nvitucci]

I've tried a Gremlin query against a standard Titan graph (the Graph of Gods) to fetch the indexed keys:

from bulbs.titan import Graph
g = Graph()
g.gremlin.query('g.getIndexedKeys(Vertex.class)')

It works but I get a "TypeError: string indices must be integers" exception when I loop over the results, while I should get four results ("reason", "age", "name", "place"). If I run a g.V query (g.gremlin.query('g.V')) and loop over the results everything works correctly.