No module named 'cv2'

After spending hours trying out others’ suggestions, I still can’t get OpenCV to work. I’d like to build a Python script that checks an image’s/PDF’s color at a certain area (it’s for a printing company to verify that documents have a 0.5mm white border, as this is their machine’s preferred format). That said, I’m planning on using OpenCV’s color detection capabilities to set an RGB tolerance for a document’s contours.

I’ve tried installing OpenCV with brew, brew install homebrew/science/, sudo pip, sudo pip3, pip and pip3, but I keep getting the following error:

ModuleNotFoundError: No module named 'cv2'

What confuses me most is that it seems I’ve successfully installed OpenCV when I enter pkg-config opencv --cflags in terminal:

-I/usr/local/Cellar/opencv/3.3.1_1/include/opencv -I/usr/local/Cellar/opencv/3.3.1_1/include

Is the wrapper no longer supporter for Python 3.6? If so, where could I get a similar package?

Here’s what I’m working with so far:

import cv2
import numpy as np

img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

contours,_ = cv2.findContours(img, cv2.RETR_LIST, cv2.cv.CV_CHAIN_APPROX_NONE)

lst_intensites = [(255, 255, 255)]

for i in range(len(contours)):
    cimg = np.zeros_like(img)
    cv2.drawContours(cimg, contours, i, color=255, thickness=-1)

    pts = np.where(cimg == 255)
    lst_intensities.append(img[pts[0], pts[1]])