#!/usr/bin/env python2.7
import cv

CAMERA_INDEX = 0

cv.NamedWindow("Video", cv.CV_WINDOW_AUTOSIZE)
capture = cv.CaptureFromCAM(CAMERA_INDEX)

while True:
    frame = cv.QueryFrame(capture)
    cv.ShowImage("w1", frame)

출처: http://calebmadrigal.com/intro-opencv-python/