import board 
import digitalio 
import time 

greenLED = digitalio.DigitalInOut(board.GP26)  # yellow
greenLED.direction = digitalio.Direction.OUTPUT 
redLED = digitalio.DigitalInOut(board.GP0)  # red
redLED.direction = digitalio.Direction.OUTPUT 
yellowLED = digitalio.DigitalInOut(board.GP1)  # green
yellowLED.direction = digitalio.Direction.OUTPUT 

button = digitalio.DigitalInOut(board.GP27) 
button.direction = digitalio.Direction.INPUT 
button.pull = digitalio.Pull.DOWN 

while True:
    state = button.value
    
    if state == True: # Establish a condition to light up all LEDs 
    when the button will press
        greenLED.value = True  
        redLED.value = True
        yellowLED.value = True
        
    else: # Establish a condition to light up only one LED
        greenLED.value = True  # Set LED to turn on
        redLED.value = False  # Set LED to turn down
        yellowLED.value = False  # Set LED to turn down
        time.sleep(1)
        
        redLED.value = True  # Set LED to turn on
        greenLED.value = False  # Set LED to turn down
        yellowLED.value = False  # Set LED to turn down
        time.sleep(1)
        
        yellowLED.value = True  # Set LED to turn on
        greenLED.value = False  # Set LED to turn down
        redLED.value = False  # Set LED to turn down
        time.sleep(1)