How to fix "object has no attribute" error in Python?

Question

Python

The error itself is:
Traceback (most recent call last):
File "./example.py", line 26, in
cv = cv2.SURF( 400 )
AttributeError: 'module' object has no attribute 'SURF'
What could be the problem?

Answer 1

Reinstalling OpenCV helped.

Answer 2

cv2 (whatever it is) does not have the SURF attribute you are trying to call.

Answer 3

Check the version of OpenCV, in new versions some modules have been moved to a separate opencv_contrib project and they are not there by default.