Why dask delayed do nothing?

Question

I am using dask to process files line by line. However, dask seems that do not do anything. My code logic is as follows:

import dask
from dask import delayed
from time import sleep

@dask.delayed
def inc(x):
    sleep(1)
    print(x)


def test():
    for i in range(5):
        delayed(inc)(i)

dask.compute(test())

However, no any outputs in console. Why?

Answer 1

Your function test does not return anything.

Perhaps you meant to do something like

def test():
    out = []
    for i in range(5):
        out.append(inc(i))
    return out

(note that you already decorated inc with delayed, there is no need to call delayed(inc) again)