That's the worse way to checking it's empty, even if pipeline was a python list
And this pipeline is interesting, but in this case, it's useful for setting values, not reading them.
It implements __len__ so there's your answer
if len(request.pipeline) > 0:
(Yes, if len returns 0 it's evaluated as false, just tested this)
But for the 2nd I would prefer
if not len(request.pipeline):
you want to execute only if it has a length.
cool though, I am using pipelines for something at work and read this post and realized I was executing even if there was nothing to execute!
I don't know why I put the 'not' there