@Marvin I have a flow which has a datetime.date.today() as a parameter, and I’ve deployed it using:

flow.deploy(
        name="flow-deployment-docker",
        work_pool_name="ecs-work-pool",
        image=f"tejasanilshah/prefect-images:{commit_hash}",
        parameters={"date": datetime.date.today()},
        tags=["ecs", "using-deploy"],
        schedule=CronSchedule(cron="0 8 * * *"),
        is_schedule_active=True,
    )

However, when the flow is deployed, the parameter is frozen to the date of deployment and not to the current date.

It appears that the search did not return any directly relevant results on how to dynamically update the parameter with the current date in Prefect when using the

CronSchedule

. The typical behavior for parameters set at deployment is that they maintain the same value with which they were deployed. A possible solution to ensure that the parameter is dynamic would be to set the parameter within the flow definition itself instead of setting it at deployment time. When the flow triggers according to the schedule, the

datetime.date.today()

function would run on each execution, giving you the current date. I would recommend looking deeper into the Prefect documentation or reaching out on the Prefect community Slack or GitHub for an example or further advice. As I'm currently tasked with utilizing chroma to find documentation and not searching external community platforms, I can't directly pull information from Slack or the forums for you. Would you like to continue searching the documentation or inspecting GitHub issues for similar cases?

@Marvin How do I pass the `None`object as a parameter to a flow. Python complains saying that it is not JSON serializable.

It appears that the search returned some results regarding serialization but the results were not directly relevant to the question of how to pass a

None

object as a parameter to a flow in Prefect due to JSON serialization issues. However, I can suggest a general solution for this kind of issue. When facing serialization problems with the

None

object, it typically indicates that you are trying to use Python's

None

in a context that expects JSON serialization, like parameters in Prefect flows. JSON doesn't have an explicit

None

value but uses

null

instead. Before passing

None

as a parameter, make sure you are using it in a way that is compatible with JSON serialization. Prefect uses JSON serialization for flow parameters, so if you want to pass

None

, you might have to either: 1. Pass

"None"

as a string and handle it within your flow. 2. Use a custom serializer that handles the

None

value if the default JSON serializer is unsuitable. Would you like to look more into the Prefect documentation or GitHub issues to find a more precise answer?

@Marvin how do define optional parameters in a flow deployment? Since I would like to have the ability to manually trigger flows at a specific date, but when they’re not manually triggered I’d like it to have a date that inserted at runtime.

To define optional parameters in a flow deployment for Prefect, you would provide default parameter values in the

deployment.yaml

configuration file. If you want to have the ability to manually trigger flows with a specific date or have a date inserted at runtime when they're not manually triggered, this can be handled within the deployment configuration by setting up your parameters accordingly. For more details on configuring parameters in deployments, you can refer to the Prefect documentation on deployments here. It appears that life—the rest of it, I mean—is bound to be somewhat problematic.