I need to use the Homebrew version of Python rather than the system version of Python. I have a clean install of macOS Sierra (10.12.5).
I first installed homebrew and then updated ~/.bash_profile using nano ~/.bash_profile.
Then I added this into the file:
# Homebrew
export PATH=/usr/local/bin:$PATH
Then, I needed to manually source the ~/.bash_profile file to ensure the changes have been reloaded using source ~/.bash_profile.
I installed python using brew install python and tried to link using brew linkapps python
The output was this:
Warning: Already linked: /usr/local/Cellar/python/2.7.13_1
To relink: brew unlink python && brew link python
Gautams-Air:~ gautam$ which python
/usr/bin/python
Gautams-Air:~ gautam$ python -V
Python 2.7.10
Gautams-Air:~ gautam$ brew linkapps python
Warning: brew linkapps has been deprecated and will eventually be removed!
Unfortunately brew linkapps cannot behave nicely with e.g. Spotlight using
either aliases or symlinks and Homebrew formulae do not build "proper" .app
bundles that can be relocated. Instead, please consider using brew cask and
migrate formulae using .app's to casks.
Linking: /usr/local/opt/python/IDLE.app
Linking: /usr/local/opt/python/Python Launcher.app
Linked 2 apps to /Applications`
Using which python the output was:
/usr/bin/python
It should have been: /usr/local/bin/python
I also tried using: brew unlink python && brew link python
Also using python -V it shows Python 2.7.10 although the current version in Homebrew is Python 2.7.13
How do I use the Homebrew version of Python instead of the system version of Python? - How do I do the linking?
USING:
macOS Sierra (10.12.5)
Due to a recent change in the Homebrew formula for python2 starting with version 2.7.13_1, Homebrew no longer creates a symlink for python to the Homebrew version.
Instead, it only installs and symlinks python2. You will need to take an additional step to use it instead of the system version of Python.
See the "Caveats" section in this package's info. Below is an example, but note that the actual PATH to export is generated and may be different on your machine.
$ brew info python2
... snip ...
=> Caveats
This formula installs a python2 executable to /usr/local/bin.
If you wish to have this formula's python executable in your PATH then add
the following to ~/.bash_profile:
export PATH="<... some path ...>:$PATH"
... snip ...
Edit: Homebrew talked more about this change in their recent release notes.
I had installed OpenCV following these steps. After trying to compile one example, I got this error:
OpenCV Error: Unspecified error (The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script) in cvNamedWindow, file /home/nick/.Apps/opencv/modules/highgui/src/window.cpp, line 516
terminate called after throwing an instance of 'cv::Exception'
what(): /home/nick/.Apps/opencv/modules/highgui/src/window.cpp:516: error: (-2) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function cvNamedWindow
CMakeLists.txt
cmake_minimum_required(VERSION 2.8.4)
project(threadTest)
find_package( OpenCV REQUIRED )
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wall -Wextra -pthread")
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "/home/nick/ClionProjects/threadTest")
set(SOURCE_FILES main.cpp)
add_executable(threadTest ${SOURCE_FILES})
target_link_libraries( threadTest ${OpenCV_LIBS} )
How can I solve it?
First check whether libgtk2.0-dev is installed properly. If you have installed aptitude package manager, run the following:
sudo aptitude search libgtk2.0-dev
It should return like this:
i libgtk2.0-dev - development files for the GTK+ library
p libgtk2.0-dev:i386 - development files for the GTK+ library
You need to build the files once again. Locate your OpenCV folder. Create a new folder and name it Release. Enter into this folder. For example,
cd /home/user_name/OpenCv
mkdir Release
cd Release
Now build using CMake with following command:
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_QT=ON -D WITH_GTK=ON -D WITH_OPENGL=ON ..
Remember to put WITH_GTK=ON during CMake.
After this step, enter the command,
make
sudo make install
This should resolve your problem. If you have broken dependencies for libgtk2.0-dev, then install a fresh copy of libgtk2.0-dev using aptitude.
sudo aptitude install libgtk2.0-dev
If you installed OpenCV using the opencv-python pip package, be aware of the following note, taken from opencv-python:
IMPORTANT NOTE
macOS and Linux wheels have currently some limitations:
video related functionality is not supported (not compiled with FFmpeg)
for example cv2.imshow() will not work (not compiled with GTK+ 2.x or Carbon support)
Also note that to install from another source, first you must remove the opencv-python package.
To install OpenCV in Ubuntu, I followed this guide, and it worked perfectly fine: Ubuntu 16.04: How to install OpenCV
In order to improve Nic Szer's answer I want to explain how to fix this error on macOS in three simple steps.
Remove installed OpenCV version to avoid messing up later
pip3 uninstall opencv-python
Lower your Python version to 3.5 (the current version, 3.6, has problems with Conda which we will use to install OpenCV)
conda install python=3.5
Finally, use Conda to install a working version of OpenCV
conda install -c menpo opencv3
And then voilà: OpenCV will start working on your macOS (macOS v10.12.4 (Sierra)).
For Windows, just uninstall the OpenCV package:
pip uninstall opencv-python
And reinstall:
pip install opencv-python
In case what is mentioned in previous answers doesn't work, try:
pip install opencv-python
for Python 2, or
pip3 install opencv-python
for Python 3.
For me (Arch Linux, Anaconda with Python 3.6), installing from the suggested channels menpo or loopbio did not change anything. My solution was to
install pkg-config (sudo pacman -Syu pkg-config),
remove opencv from the environment (conda remove opencv) and
re-install opencv from the conda-forge channel (conda install -c conda-forge opencv)
conda list now returns opencv 3.3.0 py36_blas_openblas_203 [blas_openblas] conda-forgeand all windows launched using cv2 are working fine.
I have had to deal with this issue a couple of times, and this is what has worked consistently thus far:
conda remove opencv
conda install -c menpo opencv
pip install --upgrade pip
pip install opencv-contrib-python
I have the solved using Anaconda 3 installing on Ubuntu 16.04 (Xenial Xerus).
I have used the PyCharm editor for my Python code.
I am using the Python 3.6 version.
I solved the issue using these processes.
IDEA: we need to install the package opencv-contrib-python package from PyCharm.
After installing OpenCV using vcpkg on Ubuntu, there is a known issue with vcpkg where you'll end up with the exact same error message as the top of this post with no access to highgui:
OpenCV(4.3.0) Error: Unspecified error (The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support.
If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script) in cvNamedWindow,
file .../vcpkg/buildtrees/opencv4/src/4.3.0-0c6047baf6.clean/modules/highgui/src/window.cpp, line 634
Caught exception: OpenCV(4.3.0) .../vcpkg/buildtrees/opencv4/src/4.3.0-0c6047baf6.clean/modules/highgui/src/window.cpp:634:
error: (-2:Unspecified error) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support.
If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function 'cvNamedWindow'
The problem is vcpkg passes in the build option -DWITH_GTK=OFF when building OpenCV. The open issue: https://github.com/microsoft/vcpkg/issues/12621
The workaround is the following:
edit the file vcpkg/ports/opencv4/portfile.cmake
find the line that says -DWITH_GTK=OFF and change it to say -DWITH_GTK=ON
run ./vcpkg remove opencv4
run sudo apt-get install libgtk2.0-dev pkg-config
reinstall OpenCV with ./vcpkg install opencv4 or whichever vcpkg command you used
I have Ubuntu 16.04 LTS (Xenial Xerus) environment with GTK 3 preinstalled.
I got the same error for Caffe build (master branch),
Try the following steps, may be it should work for you.
sudo apt-get install libgtk-3-dev
cmake .. (WITH_GTK=ON and other settings),
make
And bingo, the error was gone... in my Python Caffe code
Please note:
The CMake configuration should reflect GTK+ 3.x instead of GTK+ 2.x:
GUI:
-- QT: NO
-- GTK+ 3.x: YES (ver 3.18.9)
-- GThread : YES (ver 2.48.2)
-- GtkGlExt: NO
-- OpenGL support: NO
-- VTK support: NO
I have fixed my issue using this,try it
pip install opencv-python-headless==4.5.3.56
pip install opencv-contrib-python==4.5.3.56
pip install opencv-python==4.5.3.56
I had the same problem, and fixed it by simply reinstalling opencv.
There is no need to uninstall it first.
My issue was solved after installing opencv-contrib-python:
pip install opencv-contrib-python
I tried several of the previous answers the one that worked for me in ubuntu is mentioned in the following steps:
Firstly, remove the current opencv package that is installed in your system by typing in the following command in the terminal conda remove opencv.
If your Python version is 3.6 or above then change it into the stable version which can be done by typing in conda install python=3.5.
Later on, install the opencv package again by giving the following input in terminal conda install -c menpo opencv3
I had the same issue and it has been resolved after uninstalling opencv-python and doing a fresh install.
pip uninstall opencv-python
pip install opencv-python
try this. It worked for me
sudo apt-get install cmake cmake-curses-gui libgtk2.0-dev
pip install opencv-contrib-python
reinstalling and installing with the above command solved my issue but just after closing all instances of pyhton and anaconda because apparently a cache version of the library was being kept in my system.
Hence, uninstall opencv (try with pip and conda), close the IDE and reboot it, check if you can import opencv. If you still can import it, try to run the code:
help(cv2)
and check where the files are stored and delete that folder.
Repeat the process untill you are sure it is uninstalled so you can reinstall opencv full package (option 2 - see https://pypi.org/project/opencv-python/ )
I had the same issue and it has been resolved after uninstalling opencv-python version 4 and then installing the OpenCV version 3.
pip install opencv-python==3.4.9.33
I have fixed this issue by replacing
cvDestroyWindow("showImage");
by
cvDestroyWindow("ShowImage");
I am building an Arch Linux system from scratch, and presently there is no Python in the system. I could install Python2.7 by using this command:
pacman -S python2
But when I try to install some package for python like this:
pacman -S python-numpy
Pacman only shows option to download Python3.x and numpy for Python3.x. There is no other option available. How can I make sure that when I search for Python stuff, it only searches based on which Python version I have installed? There is no Python3 in my system and I have no need of it at all. In my Ubuntu system, I do not specify the Python version but it is always taken care of. I have no clue how to handle this in Arch Linux.
Thanks in advance!
In Arch Linux the default Python version is 3, so all python-* packages (including python itself) are for Python3. Fortunately Python2 is still fully supported, they are just prefixed with python2-* instead. So to install numpy you would do pacman -S python2-numpy.
Also if you want to download the packages specific to python2.7 from Python Package Index you'll have to use pip2.
e.g.:
sudo pip2 install <package name>
I am trying to install the OpenGL-2.4.0.2 package manually, but after I download the tarball from Hackage and decompressed it, when I ran
sudo runhaskell Setup.hs configure
I get these:
Configuring OpenGL-2.4.0.2...
Setup.hs: At least the following dependencies are missing:
GLURaw >=1.1.0.0,
ObjectName -any,
OpenGLRaw >=1.1.0.0,
StateVar -any,
Tensor -any
But I've checked that I've already installed these:
GLURaw 1.1.0.1
ObjectName 1.0.0.0
OpenGLRaw 1.1.0.2
StateVar 1.0.0.0
Tensor 1.0.0.1
And I've tried reinstall these but no avail.
I use GHC 7.2.1, cabal-install 0.8.0 with Cabal 1.8.0.2, under Ubuntu 11.04.
Thanks for any suggestions!
If you installed the dependencies using cabal-install (the cabal command line programme), they are by default installed in the user package-db. But when you install a package using the runhaskell ./Setup.hs way, it does global installs by default and therefore cannot use packages from the user-db. Try installing the package in the user-db,
runhaskell ./Setup.hs configure --user
or reinstall the dependencies in the global db, cabal install --global foo.
How do you install Boost on MacOS?
Right now I can't find bjam for the Mac.
You can get the latest version of Boost by using Homebrew.
brew install boost.
Download MacPorts, and run the following command:
sudo port install boost
Just get the source, and compile Boost yourself; it has become very easy. Here is an example for the current version of Boost on the current macOS as of this writing:
Download the the .tar.gz from https://www.boost.org/users/download/#live
Unpack and go into the directory:tar -xzf boost_1_50_0.tar.gz
cd boost_1_50_0
Configure (and build bjam):
./bootstrap.sh --prefix=/some/dir/you/would/like/to/prefix
Build:
./b2
Install:./b2 install
Depending on the prefix you choose in Step 3, you might need to sudo Step 5, if the script tries copy files to a protected location.
Unless your compiler is different than the one supplied with the Mac XCode Dev tools, just follow the instructions in section 5.1 of Getting Started Guide for Unix Variants. The configuration and building of the latest source couldn't be easier, and it took all about about 1 minute to configure and 10 minutes to compile.
Install both of them using homebrew separately.
brew install boost
brew install bjam
Fink appears to have a full set of Boost packages...
With fink installed and running just do
fink install boost1.35.nopython
at the terminal and accept the dependencies it insists on. Or use
fink list boost
to get a list of different packages that are availible.
Install Xcode from the mac app store.
Then use the command:
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
the above will install homebrew and allow you to use brew in terminal
then just use command :
brew install boost
which would then install the boost libraries to <your macusername>/usr/local/Cellar/boost
In order to avoid troubles compiling third party libraries that need boost installed in your system, run this:
sudo port install boost +universal
Try +universal
One thing to note: in order for that to make a difference you need to have built python with +universal, if you haven't or you're not sure you can just rebuild python +universal. This applies to both brew as well as macports.
$ brew reinstall python
$ brew install boost
OR
$ sudo port -f uninstall python
$ sudo port install python +universal
$ sudo port install boost +universal
you can download bjam for OSX (or any other OS) here
If you are too lazy like me:
conda install -c conda-forge boost