#import packages
from gpiozero import Button, MotionSensor
from picamera import PiCamera
from time import sleep
from signal import pause

#create objects 
button = Button(2)
pir = MotionSensor(4)
camera = PiCamera()

#start the camera
camera.rotation = 180
camera.start_preview()

#image image names
i = 0

#stop the camera when the momentary switch pressed
def stop_camera():
    camera.stop_preview()
    #exit the program
    exit()

#take a picture when motion detected
def take_picture():
    global i
    i = i + 1
    camera.capture('/home/pi/Desktop/image_%s.jpg' % i)
    print('A picture has been taken')
    sleep(10)

#assign a function that runs when the momentary switch pressed
button.when_pressed = stop_camera
#assign a function that runs when motion detected
pir.when_motion = take_picture

pause()