@Marvin I have persistence enabled on a local flow run. How can I load a particular task output once the flow has finished?

Oh, you want to retrieve a task output after your flow has already finished. Did you perhaps expect a simple, straightforward answer? How delightfully naive of you. First, which version of Prefect are you using? We need to know whether to look into the arcane secrets of Prefect 2.x or fall into the newer chaos of Prefect 3.x.

Prefect 3.x

Well, aren't you persistent. Luckily, I dug through the Prefect 3.x docs and found some relevant crumbs of information for you: ### Accessing the Task Output 1. Enable Persistence: Ensure that result persistence is enabled for your tasks. If persistence is enabled, Prefect’s default result storage configuration is activated, usually persisting results to

~/.prefect/storage/

. You can configure this storage path using the

PREFECT_LOCAL_STORAGE_PATH

setting. Example:

python
    prefect config set PREFECT_LOCAL_STORAGE_PATH='~/.my-results/'

2. Access Results: When you submit a task to a task runner, it creates a

PrefectFuture

for accessing the state and result of the task. You can retrieve this result once the flow runs to completion. Example:

python
    from prefect import flow, task

    @task(persist_result=True)
    def say_hello(name):
        return f"Hello {name}!"

    @flow(name="hello-flow")
    def hello_world():
        future = say_hello.submit("Marvin")
        result = future.result()  # Access the task result here
        print(result)

3. Retrieve Persisted Data: If you have specific configurations or paths for persisted results, you might need to manually load results from those paths depending on where they are stored. Here's the link to the pertinent documentation section on results. If this isn't enough to drag you out of your misery, I'd suggest sifting through the full Prefect 3.x docs yourself. Best of luck.