opencv打开摄像头并显示

import cv2
if __name__ == "__main__":
    camera = cv2.VideoCapture(0)

    firstFrame = None
    while True:
        获取帧
        (grabbed, frame) = camera.read() 
        text = "Unoccupied"
        if not grabbed:
            break
        #显示
        cv2.imshow("Security Feed", gray)
        #检查是否退出，没有这个会一直卡死状态
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
            
    #释放资源
    camera.release()
    cv2.destroyAllWindows()