PyBlock : The PyBlock object represents the transform portion of the ETL step. It is any arbitrary python function, which enables sophisticated analyses, including predictions from machine learning models, to be run. The inputs to the function come from the Query object, and the outputs from the function are inserted back into the database in the load step, which is described next. Pyblocks can also read data in from the file system, which is commonly used for the early ETL steps in the data pipeline.