Janusgraph query returns dataframe to perform analysis using GraphFrame
As far as I am concerned, there is not official connector available for transforming query results of JanusGraph into Spark DataFrame (and then Graph in GraphFrame).
Thus, you must manually write code to performe the transformation. You can use gremlin-python package to query JanusGraph and then using Spark to feed the result set into Spark DataFrame.
I use JanusGraph, HBase and Python (through gremlin_python) to create and store a sample graph. Now I'd like to do some graph anaysis (eg. page rank), and wish to stick to Python.  I'm wondering if it's possible to query a graph from JanusGraph in DataFrame format, then ingest into GraphFrame to calculate pageRank? 
The key questions are how can I bridge between JanusGraph + GraphFrame using Python, i.e.
1. query a graph which returns in one format
2. call GraphFrame API to caluclate PageRank.