trouble installing opencv on a mac (after opencv worked fine a few months ago)

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(I posted the same question on stackoverflow: https://stackoverflow.com/questions/5...)

I have opencv installed on my mac which was working a few months ago but doesn't work anymore.

I have the following specificities. - OpenCV: 3.4.3.1 - Operating System / Platform: macOS 10.14 - Python 3.6.5

I tried to reload a python script where I used opencv. However, I got the following error message:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: dlopen(/anaconda3/lib/python3.6/site-packages/cv2.so, 2): Library not loaded: /usr/local/opt/ilmbase/lib/libImath-2_2.12.dylib
  Referenced from: /usr/local/Cellar/opencv/3.4.1_4/lib/libopencv_imgcodecs.3.4.dylib
  Reason: image not found

I then tried to re-install opencv with the step by step explanation of this site with which I successfully installed opencv for the first time.

1. determine which version of opencv I have on my machine

After having written cd /usr/local/Cellar/opencv and ls I get: 3.4.1_4 3.4.3 3.4.3_1. So I conclude that the latest version on my machine is 3.4.3_1 which is in /usr/local/Cellar/opencv/3.4.3_1/cv2.cpython-37m-darwin.so

1. Determine the path for package in python

Then if i do the following $ cd /usr/local/Cellar/opencv/3.4.3_1 and $ cd lib, I get (among others): python3.7. Then I do the following: $ cd python3.7 and then $ cd site-packages and $ pwd, I get: /usr/local/Cellar/opencv/3.4.3_1/lib/python3.7/site-packages

1. add the cv2.<version>.so to System python

I enter then python with $ python3 and get

Python 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 03:03:55) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

Question N°1 Isn't it weird that it says version 3.6.5 and opencv seems to have a lib 3.7 (and no 3.6)

type >>> import sys and then >>> print(sys.path)and get the following list:

['', '/Library/Frameworks/Python.framework/Versions/3.6/lib/python36.zip',
'/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6', 
'/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib-dynload', 
'/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages']

I then enter:

$ ln -s /usr/local/Cellar/opencv/3.4.3_1/lib/python3.7/site-packages/cv2.cpython-37m-darwin.so /Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/cv2.so

1. Add OpenCV to Virtualenvs

I then add the following command:

$ mkdir ~/Dev
$ cd ~/Dev
$ virtualenv -p python3 newcvtest
$ cd newcvtest
$ source bin/activate
(newcvtest) $ python --version 
Python 3.6.5
$ pip install numpy
$ cd lib/python3.6/site-packages
$ ln -s /usr/local/Cellar/opencv/3.4.3_1/lib/python3.7/site-packages/cv2.cpython-37m-darwin.so

After that the installation should be finished. However I still get the same error message

What should I do?