Is it possible to map over kwargs as asked in this Q&A? https://github.com/PrefectHQ/prefect/discussions/5014 Context: I’m trying to create a cross-product of multiple lists to map over. I want to operate on the downstream values by taking them as kwargs. Inspiration from this question answered by @Kevin Kho https://prefect-community.slack.com/archives/CL09KU1K7/p1645196983284599

from prefect import Flow, task
from pprint import pformat


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


@task
def letters():
    return ["a", "b", "c"]


@task
def cross_product(numbers, letters):
    res = []
    for letter in letters:
        for num in numbers:
            res.append({"num": num, "letter": letter})
    return res


@task
def pretty_print(**kwargs):
    print(pformat(kwargs))


with Flow("...") as flow:
    n = numbers()
    l = letters()
    map_items = cross_product(n, l)
    pretty_print.map(map_items)

flow.run()

I get the following error:

Traceback (most recent call last):
  File "flow.py", line 33, in <module>
    pretty_print.map(map_items)
  File "prefect/core/task.py", line 760, in map
    *args, mapped=True, upstream_tasks=upstream_tasks, flow=flow, **kwargs
  File "prefect/core/task.py", line 674, in bind
    callargs = dict(signature.bind(*args, **kwargs).arguments)  # type: Dict
  File "inspect.py", line 3015, in bind
    return args[0]._bind(args[1:], kwargs)
  File "inspect.py", line 2942, in _bind
    'too many positional arguments') from None
TypeError: too many positional arguments

I believe you really just can’t do it for **kwargs but I think you can just accept the dict and then work with that right?

yeah we could use it just as an

items

dictionary. Can we dynamically rename the task with

task_run_name="number: {items[num]} letter: {items[letter]}"

?

Someone told me it worked if items is the name of the input into the task