Hi, flyte team! I would like to ask

Promise object

of task's return values.

from flytekit import workflow, task, dynamic, conditional
from flytekit.core.promise import Promise

@task
def t1() -> bool:
    return True


@task
def t2() -> bool:
    return False


@workflow
def wf() -> bool:
    test = t1()
    print(test)
    return t2()


if __name__ == "__main__":
    print(wf())

when I run this sample codes through

pyflyte

, a task returns

Promise object

, and literal or objects I expect are wrapped in

Promise

. So, here is my question, how I unwrap this promise object? I would like to use the expected value from the function. Thank you!

@gifted-house-14547, you can unwrap promises in a Flyte task.

@tall-lock-23197 would you explain it in detail? I got a result below

Promise(node:n0.o0)
Resolved(o0=scalar {
  primitive {
    boolean: true
  }
}
)

Just pass the promise to a task

I am looking for other solution, not to pass Promise object to the other tasks, but unwrap it in workflow itself. official docs link I have already knew @freezing-airport-6809 mentioned below

from flytekit import workflow, task, dynamic, conditional
from flytekit.core.promise import Promise

@task
def t1() -> bool:
    validation(return_value)
    return True


@task
def t2(a:bool) -> bool:
    print(a)
    return False


@workflow
def wf() -> bool:
    test = t1()
    # print(test)
    return t2(a=test)


if __name__ == "__main__":
    print(wf())

May I know why you want to access it in the workflow?

@tall-lock-23197 yeah! that's exactly what I wanted!

Okay, but why do you want to access it? I’d like to know your use-case.

@gifted-house-14547 - Promise objects are “promises” that means they promise that data will be available at runtime. At static time, when workflows are create these are not available and cannot be unwrapped. Workflow code does not run when a workflow is being executed. so there is no way to add code in the workflow to inspect the promise. Only way to do that is to use

@dynamic

, but it is still limited to the inputs to a dynamic task.