Run a flow

Looking for the latest Prefect 2 release? Prefect 2 and Prefect Cloud 2 have been released for General Availability. See https://docs.prefect.io/ for details.

Now that you have Prefect installed, you're ready to run a flow.

A flow is a container for tasks and shows the direction of work and the dependencies between tasks.

To run your flow, paste the code below into an interactive Python REPL session:

import prefect
from prefect import task, Flow

@task
def hello_task():
    logger = prefect.context.get("logger")
    logger.info("Hello world!")

with Flow("hello-flow") as flow:
    hello_task()

flow.run()

You should see the following logs after running flow.run():

[2020-01-08 23:49:00,239] INFO - prefect.FlowRunner | Beginning Flow run for 'hello-flow'
[2020-01-08 23:49:00,242] INFO - prefect.FlowRunner | Starting flow run.
[2020-01-08 23:49:00,249] INFO - prefect.TaskRunner | Task 'hello_task': Starting task run...
[2020-01-08 23:49:00,249] INFO - prefect.Task: hello_task | Hello world!
[2020-01-08 23:49:00,251] INFO - prefect.TaskRunner | Task 'hello_task': finished task run for task with final state: 'Success'
[2020-01-08 23:49:00,252] INFO - prefect.FlowRunner | Flow run SUCCESS: all reference tasks succeeded

And that's it. You have run your first Prefect flow using Prefect Core!