MultiEchoLaserScan versus LaserScan problems

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I have a ROS python node working great using urg_node (ubuntu kinetic). I was using the scan topic and it returns the distances using dist = np.array(data.ranges) in the callback. HOWEVER, I have had to go to multiecho and now I have the topic echoes. I can read MultiEchoLaser message fine but the distance data is now buried in subtopic LaserEcho. If I try to read data.ranges in the callback I get the distance data, but it includes the echoes keyword. e.g echoes : [1.2389] and so on. How do I get just the float32 distance data similar to what I got using scan ? All help appreciated.