In train.py:
run.tag('run_type', value='training')
In later step:
#Retrieve associated run, workspace and experiment
run = Run.get_context()
ws = run.experiment.workspace
exp = run.experiment
parent_run = run.parent
# Retrieve training run via parent run of pipeline
training_run = list(parent_run.get_children(tags={'run_type': 'training'}))[0]