Creating tasks

To create a task, simply decorate a function with Kohlrabi task decorator.

@kh.task
def hello():
    print("Hello, world!")

Then, inside your main method (or __name__ check), call the task as if it was a function.

if __name__ == "__main__":
    hello()

If you check the console of the server process, it will have printed Hello, world!.

More advanced tasks

An example of a more advanced task would be an addition task.

@kh.task
def add(a, b):
    return a + b

Inside your main method, call the add task with the parameters chosen:

fut = add(1, 2)

This returns a ClientTaskResult object, which you can use to get the result of the task.

print("Added together 1 and 2 to get:", fut.result)

Note that ClientTaskResult.result is blocking, and will wait until the task has finished to get the result of the task. If you wish to only wait a certain amount of time, use the ClientTaskResult.result_with_timeout method.

print("Added together 1 and 2 to get:", fut.result_with_timeout(1))

Chaining tasks

If you wish to chain tasks together, use the yield from keywords. On the server side, a task is just a wrapped coroutine, meaning you can use it as if it was a coroutine.

@kh.task
def add_two(a):
    return a + 2

@kh.task
def get_four():
    four = yield from add_two(2)
    return four