One last question for today Mapping Tasks is this still TODO

Question

One last question for today Mapping Tasks is this still TODO on Prefect 2 0

Tim Enders · Answer

Or am I wanting Async tasks instead Do you guys have documentation on those yet

Zanie · Answer

Both sync and async tasks can run concurrently Here s brief documentation on async tasks <https orion docs prefect io async concurrency>

Zanie · Answer

Mapping via a ` map` operator is also on the roadmap and is currently being designed

Tim Enders · Answer

OK we are liberal users of ` map` and the `DaskExecutor` in 1 2 would you recommend trying to rewrite as async or should I wait until ` map` is ready Full adoption for us is waiting until it is out of beta I am just trying to work ahead so waiting isn t a big deal

Zanie · Answer

I d wait for the mapping operator if you want to spawn multiple mapped branches without blocking Otherwise you can just use a for loop to iterate over the input value The tasks will run concurrently without using async

Tim Enders · Answer

Hmmm i will probably revisit this tomorrow as my brain is done for the day

Tim Enders · Answer

OK back on this with a fresh brain which wants to say that the for loop is inherently syncronous so wouldn t it defeat the purpose of parallelizing with Dask But I think I am going to try it out and see

Tim Enders · Answer

Getting this ```RuntimeError An attempt has been made to start a new process before the current process has finished its bootstrapping phase This probably means that you are not using fork to start your child processes and you have forgotten to use the proper idiom in the main module if name == main freeze support The freeze support line can be omitted if the program is not going to be frozen to produce an executable ``` so I must be doing something wrong Asking in a new thread

Zanie · Answer

The for loop is synchronous but all you re doing is submitting task runs in it

Zanie · Answer

That error is related to Dask multiprocessing you need to call the flow within an if name == main block like that

Tim Enders · Answer

Ah HA typo in the if name == main block