python-opencv调用电脑自带摄像头并显示

import cv2

cap = cv2.VideoCapture(0)
ret, frame = cap.read()
while ret:
    # get a frame

    # show a frame
    cv2.imshow("capture", frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()