Cannot find reference 'xxx' in '__init__.py | __init__.py' at PyCharm

Python
1

Anaconda + PyCharm (latest version)

When I use cv2, I see many of warning. Can someone help me?

— code —
import cv2 as cv

img = cv.imread(“Resources/Office.jpg”, cv2.IMREAD_GRAYSCALE)
cv.namedWindow(“Office”)
cv.imshow(‘Office’, img)

res1 = cv.GaussianBlur(img, (0, 0), 2)
cv.namedWindow(“Office_Sigma=2”)
cv.imshow(‘Office_Sigma=2’, res1)

res2 = cv.GaussianBlur(img, (0, 0), 5)
cv.namedWindow(“Office_Sigma=5”)
cv.imshow(‘Office_Sigma=5’, res2)

res3 = cv.GaussianBlur(img, (0, 0), 10)
cv.namedWindow(“Office_Sigma=10”)
cv.imshow(‘Office_Sigma=10’, res3)

cv.waitKey()
cv.destroyAllWindows()
— end —

— Warning —
Cannot find reference ‘imread’ in ‘init.py | init.py’
Cannot find reference ‘namedWindow’ in ‘init.py | init.py’
Cannot find reference ‘imshow’ in ‘init.py | init.py’
— end —

Also, I found pycharm recommend to use cv2.cv2. can explain what is the different cv2 vs cv2.cv2?