Hey all :slightly_smiling_face:
We got the follow...
# prefect-communityr
Robin
10/19/2020, 4:15 PMHey all 🙂
We got the following error when trying to map over a list of dictionaries.
First just to clarify: mapping over a list of dictionaries should be fine, right?
Second, what could be the reason for the message?
✔️ 1
j
Jim Crist-Harif
10/19/2020, 4:25 PMHi Robin, mapping over a list of dictionaries should be fine. The error you're getting here is happening in your task here (the actual mapping appears to be working correctly) - looks like you're getting a list where you expected a dict - perhaps you're passing in a list of lists instead?
r
Robin
10/19/2020, 4:52 PMGood point!
Thanks for the quick feedback 🙂
Robin
10/19/2020, 5:17 PMIn that case, this should work, right?
Copy code
reduce_list = task(lambda list_of_lists: reduce(list.extend, list_of_lists, []))Robin
10/19/2020, 7:17 PM Copy code
@task
def reduce_list(list_of_lists):
out = []
for l in list_of_lists:
out.extend(l)
return outj
Jim Crist-Harif
10/19/2020, 8:38 PMThat'd work, you could also make use of the new(ish)
prefect.flatten Copy code
your_task.map(flatten(list_of_lists))r
Robin
10/19/2020, 9:06 PMThanks for the tip!
that looks neat 🙂
Robin
10/19/2020, 9:06 PM@Severin Ryberg [sevberg]