Hello, I'm very much a struggling beginner.  

I've spent hours in Documentation and in Community looking for python solution to doing a history update of ATR for multiple stocks in a universe.  Also thanks to Alex who kindly helped me at an earlier stage (unfortunately before I added ATR indicator to my attempt).

I'm struggling with the final part.  I seem to have a panda row with OHLC data but it is the wrong type for passing to ATR Update; and I've run out of ideas.

Is anyone able to point me in the right direction please?

error message which is triggered from code line 127 where I want to pass to warmupindicatorbar from within onsecuritieschanged:

Runtime Error: Trying to dynamically access a method that does not exist throws a TypeError exception