Tutorial :How to install OpenCV for python


HI! I'm trying to install opencv and use it with python, but when I compile it I get no errors but I can't import cv module from python:

patrick:release patrick$ python  Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29)   [GCC 4.2.1 (Apple Inc. build 5646)] on darwin  Type "help", "copyright", "credits" or "license" for more information.  >>> import cv  Traceback (most recent call last):    File "<stdin>", line 1, in <module>  ImportError: No module named cv  

The code I used to compile it is this:

cd opencv  mkdir release  cd release  cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D BUILD_PYTHON_SUPPORT=ON  make  sudo make install  

how can I get it working with python?


brew tap homebrew/science  brew install opencv  export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH  


I found here a way to install opencv for python: http://recursive-design.com/blog/2010/12/14/face-detection-with-osx-and-python/ :)


We can install opencv for Python for Mac OS X with home-brew.

First, install home-brew:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

You can see the details for how to install homebrew. http://brew.sh

If you don't install Python, install python(brew will install python2.7):

brew install python

Maybe you want install Python3: brew install python3

Then install opencv3 for Python3:

brew install opencv3 --with-python3

If you want install opencv3 for Python(Python2.7): brew install opencv3 --with-python

OR install opencv2 for Python3: brew install opencv --with-python3

OR if you want install opencv2 for Python3: brew install opencv --with-python3

Finally, maybe you will link site-packages of opencv to the site-packages of Python.

Notes: In the follow command, /usr/local/opt/opencv3/lib/python3.5/site-packages is the directory of opencv3's site-packages, /usr/local/lib/python3.5/site-packages/ is the directory of Python3.5's site-packages.

Maybe you should change the two to your own OPENCV AND PYTHON site-packages directories.

echo /usr/local/opt/opencv3/lib/python3.5/site-packages >> /usr/local/lib/python3.5/site-packages/opencv3.pth


easy_install pip  pip install opencv-python --user  export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH  

Maybe you will use sudo,

and the path of installed may not be like mentioned.


This worked for me (change python36 to whatever version you want)

sudo port install opencv +avx2 +python36 +qt5 +contrib +eigen

I got this error and had to apply the patch there (download link)

Apply the patch with:

sudo patch /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_graphics_opencv/opencv/work/opencv-3.2.0/modules/highgui/src/window_QT.cpp ~/Downloads/patch-cpp11-narrowing-error.diff  

Then run sudo port install -N opencv +avx2 +python36 +qt5 +contrib +eigen again


You could try ctypes-opencv -- not sure why building and installing with -D BUILD_PYTHON_SUPPORT=ON didn't work for you (maybe it doesn't know where to install the Python wrappers in osx...?), but the ctypes wrappers should, in theory, work anyway.


If you have you want a simple and quick install in Windows, you can download Python(x,y). This distribution includes OpenCv. Be sure to specify that you want to install OpenCV in the installation setup, because it is not installed by default.


When using Virtual Environment

Thanks to @user495470. Follow these steps

brew update  brew install -v cmake   brew install opencv`  

If Part 1 didn't work kindly follow Part 2

Part I
Next step might work sometime, although it didn't work for me
export PYTHONPATH="/VENV_PATH/python2.7/site-packages:$PYTHONPATH"
Then check in python IDE check with import cv or import cv2

Part 2
Go to this path /usr/local/Cellar/opencv/3.4.3/lib/python2.7/site-packages/ or /usr/local/lib/python2.7/site-packages
Copy cv2.so file
Paste it /VENV_PATH/lib/python2.7/site-packages here
Then check in python IDE check with import cv or import cv2

Kindly let me know if this thing works.

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
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