script.py

import datetime

def checkIfMidnight():
    now = datetime.now()
    seconds_since_midnight = (now - now.replace(hour=0, minute=0, second=0, microsecond=0)).total_seconds()
    return seconds_since_midnight == 0
	
def main():
	print("hello world")

if __name__ == '__main__':
  while True:
		if checkIfMidnight():
			main()