Raspberry Pi - GPIO with 4-Channel Relay Module

# getting the main GPIO libraly
import RPi.GPIO as GPIO
# getting the time libraly
import time

# setting a current mode
GPIO.setmode(GPIO.BCM)
#removing the warings 
GPIO.setwarnings(False)

#creating a list (array) with the number of GPIO's that we use 
pins = [18,17,15,14] 

#setting the mode for all pins so all will be switched on 
GPIO.setup(pins, GPIO.OUT)

#for loop where pin = 18 next 17 ,15, 14 
for pin in pins :

	#setting the GPIO to HIGH or 1 or true
	GPIO.output(pin,  GPIO.HIGH)
	#wait 0,5 second
	time.sleep(0.5)
	#setting the GPIO to LOW or 0 or false
	GPIO.output(pin,  GPIO.LOW)
	#wait 0,5 second
	time.sleep(0.5)

	#Checking if the current relay is running and printing it 
	if not GPIO.input(pin) : 
		print("Pin "+str(pin)+" is working" )

#same but the difference is that  we have 
#for loop where pin = 14 next 15,17,18
# backwards

for pin in reversed(pins) :

	GPIO.output(pin,  GPIO.HIGH)
	time.sleep(0.5)

	GPIO.output(pin,  GPIO.LOW)
	time.sleep(0.5)

#cleaning all GPIO's 
GPIO.cleanup()
print "Shutdown All relays"