Deferred and Future

deferred_and_future.py

from twisted.internet import defer
from asyncio import futures, get_event_loop

d = defer.Deferred()
d.addCallback(lambda x: x + 1)
d.addCallback(lambda x: x * 2)

f1 = futures.Future()
f2 = futures.Future()
f1.add_done_callback(lambda f: f2.set_result(f.result() + 1))
f3 = futures.Future()
f2.add_done_callback(lambda f: f3.set_result(f.result() * 2))

d.callback(20)

f1.set_result(20)
get_event_loop().run_until_complete(f3)

assert d.result == f3.result() == 42