ubuntu系统下导入python-opencv问题?报错

代码如下：

import cv
import time
if __name__ == '__main__':
    cv.NamedWindow("camera",1)
    capture = cv.CaptureFromCAM(0)
    while True:
        img = cv.QueryFrame(capture)
        cv.ShowImage("camera",img)
        mm = int(time.strftime('%S',time.localtime()))
        if mm == 30:
            filename = "e:\pic\o\%s.jpg" % time.strftime('%Y%m%d%H%M%S',time.localtime())
        #time.sleep(2)
            cv.SaveImage(filename,img)
        if cv.WaitKey(10) == 27:
            break
    cv.DestroyWindow("camera")

报错代码如下：

  Traceback (most recent call last):
  File "/home/ubulinux/application/untitled/thenewtest.py", line 2, in <module>
    import cv
 ImportError: No module named cv

Process finished with exit code 1

是什么原因？