import cv2

def show_webcam(mirror=False):
    cam = cv2.VideoCapture(0)
    while True:
        ret_val, img = cam.read()
        if mirror:
            img = cv2.flip(img, 1)
        cv2.namedWindow("window", cv2.WND_PROP_FULLSCREEN)
        cv2.setWindowProperty("window",cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_FULLSCREEN)
        cv2.imshow("window", img)
        if cv2.waitKey(1) == 27:
            break  # esc to quit
    cv2.destroyAllWindows()

if __name__ == '__main__':
    show_webcam(mirror=True)