flow.py

from prefect import Flow, task

@task
def extract():
	return [1, 2, 3]

@task
def transform(x):
	return [i * 10 for i in x]

@task
def load(y):
	print("Received y: {}".format(y))

with Flow("ETL") as flow:
	e = extract()
	t = transform(e)
	l = load(t)
	flow.run()