>>> from blinker import signal
>>> started = signal('round-started')
>>> def each(round):
...     print(f"Round {round}")
...
>>> started.connect(each)

>>> def round_two(round):
...     print("This is round two.")
...
>>> started.connect(round_two, sender=2)

>>> for round in range(1, 4):
...     started.send(round)
...
Round 1!
Round 2!
This is round two.
Round 3!