Hi all if I am trying to run a Flow run through a normal IDE

Question

Hi all if I am trying to run a Flow run through a normal IDE debugger but keep seeing the value of Task outputs assigned to variables as lt Task name gt types am I returning the value of tasks wrongly or using the debugger wrong

Chris White · Answer

Hi < Steve Vandervalk> That appears to be the repr of the task For example in IPython ```from prefect import Task print Task name= Chris lt Task Chris gt ```

Steve Vandervalk · Answer

Hey yep understood I m trying to do a normal debugger flow but I guess I m unclear where the flow actually returns and assigns a Tasks output to the variable

Steve Vandervalk · Answer

if that makes sense

Chris White · Answer

hmm I don t think I m following quite yet would you mind sharing a code example of what you re referring to

Steve Vandervalk · Answer

``` with Flow Mapbox API Travel Time Retrieval and Processing as flow download geojson blob task = DownloadBlobFromAzure azure blob name = travel time segments geojson azure container = ottawa mapbox travel time inputs travel time segments geojson = download geojson blob task blob name=azure blob name azure credentials secret= AZ CREDS container=azure container ```

Steve Vandervalk · Answer

``` state = flow run executor=LocalExecutor ```

Steve Vandervalk · Answer

something as simple as that

Steve Vandervalk · Answer

but not specific to instantiated tasks functions with task decorator are the same

Chris White · Answer

that Flow code makes sense to me does it not run as you expect

Steve Vandervalk · Answer

it runs but I d like to insert a break point but the variable I assign a task to is that type instead of the returned dict or what have you

Steve Vandervalk · Answer

so I clearly don t understand something about prefect

Chris White · Answer

gotcha where are you inserting your breakpoint

Steve Vandervalk · Answer

the line after assignment say

Steve Vandervalk · Answer

inside the Flow

Chris White · Answer

so Prefect builds up a deferred computational graph meaning your code is never run until you call `flow run` so inputting a breakpoint within the build step of a Flow will not contain any results data since nothing has run yet

Steve Vandervalk · Answer

right that makes sense

Steve Vandervalk · Answer

should I step through then after the run call

Chris White · Answer

the data that is exchanged between tasks are always exchanged via Prefect States when you call `flow run` a Prefect State is returned whose `result` attribute is a dictionary mapping Tasks gt task states which have a `result` attribute themselves containing the return value from that task run

Steve Vandervalk · Answer

ah

Chris White · Answer

so using your code above you could do ```flow state = flow run flow state result travel time segments geojson result```

Chris White · Answer

to actually extract the return value of that task

Steve Vandervalk · Answer

so prefect captures it all

Steve Vandervalk · Answer

thanks that s an excellent explanation

Chris White · Answer

awesome glad I could help

Chris White · Answer

< Marvin> archive How can I inspect the outputs from my tasks

Marvin · Answer