Runs pi cam and displays as video

cam.py

# From https://stackoverflow.com/questions/27805077/display-io-stream-from-raspberry-pi-camera-as-video-in-pygame
import picamera
import pygame
import io

# Init pygame 
pygame.init()
screen = pygame.display.set_mode((320,240))

# Init camera
camera = picamera.PiCamera()
camera.resolution = (640, 480)
camera.crop = (0.0, 0.0, 1.0, 1.0)

x = (screen.get_width() - camera.resolution[0]) / 2
y = (screen.get_height() - camera.resolution[1]) / 2

# Init buffer
rgb = bytearray(camera.resolution[0] * camera.resolution[1] * 3)

# Main loop
exitFlag = True
while(exitFlag):
    for event in pygame.event.get():
        if(event.type is pygame.MOUSEBUTTONDOWN or 
           event.type is pygame.QUIT):
            exitFlag = False

    stream = io.BytesIO()
    camera.capture(stream, use_video_port=True, format='rgb')
    stream.seek(0)
    stream.readinto(rgb)
    stream.close()
    img = pygame.image.frombuffer(rgb[0:
          (camera.resolution[0] * camera.resolution[1] * 3)],
           camera.resolution, 'RGB')

    screen.fill(0)
    if img:
        screen.blit(img, (x,y))

    pygame.display.update()

camera.close()
pygame.display.quit()