import asyncio
import RPi.GPIO as GPIO

RELAY1 = 4
RELAY2 = 22
RELAY3 = 6
RELAY4 = 26

RELAY_ON = True
RELAY_OFF = False

RELAYS = [RELAY1, RELAY2, RELAY3, RELAY4]

def set_relay(r, state):
    GPIO.output(r, state)

def all_off():
    for r in RELAYS:
        set_relay(r, RELAY_OFF)

def init_relays():
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)

    for r in RELAYS:
        GPIO.setup(r, GPIO.OUT)

    all_off()

async def test():
    for r in RELAYS:
        set_relay(r, RELAY_ON)
        await asyncio.sleep(0.5)
        set_relay(r, RELAY_OFF)

if __name__ == '__main__':
    init_relays()

    loop = asyncio.get_event_loop()
    loop.run_until_complete(test())
    loop.close()