@Marvin how do I prevent a failing task from failing my flow?

@task()
def third_task(data):
    return data/0
#wait_for creates dependency
@flow()
    thirdtask = third_task(data=1, wait_for=result)

To prevent a failing task from failing your flow in Prefect 3.x, you can use the

allow_failure

utility. This will allow the task to fail without affecting the overall state of the flow. The flow's final state is determined by its return value or any uncaught exceptions, not the states of individual tasks unless explicitly handled. Here's a modified version of your code using `allow_failure`:

python
from prefect import flow, task, allow_failure

@task()
def third_task(data):
    return data / 0

@flow()
def my_flow():
    # Wrap the task call with allow_failure
    thirdtask = allow_failure(third_task)(data=1)
    # Continue with other logic if needed

my_flow()

This setup allows the

third_task

to fail without causing the entire flow to fail. You can find more details in the Prefect 3.x documentation.

@Marvin TypeError: 'allow_failure' object is not callable

It seems I was mistaken in my previous response. The

allow_failure

is not a callable function. To prevent a failing task from causing your flow to fail in Prefect 3.x, you should handle task exceptions within the flow or task itself. You can use a

try-except

block within your task to catch exceptions and handle them gracefully. Here's how you can modify your task:

python
from prefect import flow, task

@task
def third_task(data):
    try:
        return data / 0
    except ZeroDivisionError:
        # Handle the exception and return a default value or state
        return "Task failed but flow continues"

@flow
def my_flow():
    thirdtask = third_task(data=1)
    # Continue with other logic if needed

my_flow()

This way, the task will handle its own failure, and the flow can continue without being marked as failed. You can read more about handling task failures in the Prefect 3.x documentation.