Attribute Error: 'module' has no attribute BackgroundSubtractor opencv

Question

I am trying to implement the Background subtraction function on a video clip. However, I get an error saying "AttributeError: 'module' object has no attribute 'createBackgroundSubtractorMOG(). I have even tried createBackgroundSubtractorMOG2(), BackgroundSubtractorMOG(). Here is my code. Need help!

import numpy as np
import cv2

cap = cv2.VideoCapture('clip1.avi')
fgbg = cv2.createBackgroundSubtractorGMG(detectShadows=True)
while(1):
    ret, frame = cap.read()
    fgmask = fgbg.apply(frame)

    cv2.imshow('frame',fgmask)
    k = cv2.waitKey(30) & 0xff
    if k == 27:
        break
cap.release()
cv2.destroyAllWindows()