Python Non Blocking Delay

delay.py

import time


class NonBlockingDelay():
    """ Non blocking delay class """
    def __init__(self):
        self._timestamp = 0
        self._delay = 0

    def timeout(self):
	""" Check if time is up """
        return ((millis() - self._timestamp) > self._delay)

    def delay_ms(self, delay):
	""" Non blocking delay in ms """
        self._timestamp = millis()
        self._delay = delay

def millis():
    """ Get millis """
    return int(time.time() * 1000)

def delay_ms(delay):
    """ Blocking delay in ms """
    t0 = millis()
    while (millis() - t0) < delay:
        pass

main.py

from delay import NonBlockingDelay, delay_ms, millis

# blocking delay (18ms)
t0 = millis()
delay_ms(18)
print(millis() - t0)

# non blocking delay
d0, d1 = NonBlockingDelay(), NonBlockingDelay()

while True:
    try:
        if d0.timeout():
            print("d0")
            d0.delay_ms(1000)
        
        if d1.timeout():
            print("d1")
            d1.delay_ms(3000)

    except KeyboardInterrupt:
        print("Ctrl-C pressed...")
        exit()