We\'ve been running a Python pipeline in datalab that reads image files from a bucket in google cloud storage (importing google.datalab.storage). Originally we were using Direct
The most likely issue is that you need to have Dataflow install the datalab pypi module.
Typically you would do this by listing "datalab" in the requirements.txt file you upload to Dataflow. See https://cloud.google.com/dataflow/pipelines/dependencies-python