I just used brew to install Python 3 on OS X. The python3 command now starts the interpreter using brew Python 3.6, but python still opens the interpreter with the default system Python 2.7.
My understanding was that, by default, brew Python should now override system Python. (I.e., see Order of /usr/bin and /usr/local/bin and more in $PATH). In my PATH, /usr/local/bin comes before /usr/bin, so it shouldn't be a PATH issue. I have tried restarting Terminal, with no effect.
Here is my full PATH in case that is relevant.
/Users/**/.rvm/gems/ruby-1.9.3-p362/bin:/Users/**/.rvm/gems/ruby-1.9.3-p362#global/bin:/Users/**/.rvm/rubies/ruby-1.9.3-p362/bin:/Users/**/.rvm/bin:/Users/**/.rvm/bin:/Users/**/Python/PmagPy/programs/conversion_scripts2/:/Users/**/Python/PmagPy/programs/conversion_scripts/:/Users/**/Python/PmagPy/programs:/usr/local/heroku/bin:./bin:/usr/local/sbin:/usr/local/bin:/usr/local/share/npm/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/opt/X11/bin
Why isn't brew Python taking precedence? And how can I fix (or troubleshoot) this? If I can't find another option, I can create an alias, but I prefer to understand what's happening and get to the root of the problem.
Update:
I checked out the "possible duplicate" question, but my issue doesn't appear to be a linking problem:
~ brew link --overwrite --dry-run python
Warning: Already linked: /usr/local/Cellar/python/3.6.4_4
To relink: brew unlink python && brew link python
~
TL;DR Add the following to your .bash_profile (or equivalent):
export PATH="/usr/local/opt/python/libexec/bin:$PATH"
Explanation
It seems python via homebrew is now handled differently (see https://docs.brew.sh/Homebrew-and-Python).
python3 points to Homebrew’s Python 3.x (if installed)
python2 points to Homebrew’s Python 2.7.x (if installed)
python points to Homebrew’s Python 2.7.x (if installed) otherwise the macOS system Python. Check out brew info python if you wish to add
Homebrew’s 3.x python to your PATH.
Checking out brew info python hints at what you need to do:
Unversioned symlinks python, python-config, pip etc. pointing to
python3, python3-config, pip3 etc., respectively, have been
installed into /usr/local/opt/python/libexec/bin
The hint being that you therefore have to add /usr/local/opt/python/libexec/bin before /usr/bin in your path (not /usr/local/bin as stated in some sources e.g. https://docs.python-guide.org/starting/install3/osx/)
See also https://github.com/Homebrew/homebrew-core/issues/15746
One-liner to get homebrew python working:
zsh
echo -n 'export PATH="/usr/local/opt/python/libexec/bin:$PATH"' >> ~/.zshrc && source ~/.zshrc
bash
echo -n 'export PATH="/usr/local/opt/python/libexec/bin:$PATH"' >> ~/.bashrc && source ~/.bashrc
Explanation:
>> filename appends at the end of the file
source filename reloads the file
I tried a few of the proposed solutions in How to link home brew python version and set it as default, but none of them worked. Ultimately I solved this by symlinking python3 --> python:
ln -s /usr/local/bin/python3 /usr/local/bin/python
I have 3 versions of python installed on my Mac. 2 of them are through brew i.e. python2 and python3 while the native version is python. the problem is when I put brew install python it installs python2 and not python. (By saying python means the version which runs on putting that command in terminal). What should I do so that if I type python my brew installed python launches.I have my path variables set correctly and the brew installation path is ahead than that of the usr/bin The problem I am encountering is that I have nltk installed through pip, pip2 and pip3 and when I import nltk in python2 and python3 there is no problem but when I do that in python it show no module found.
Try which python in a terminal to see which python will run. Then you know and can act accordingly to fix it.
ls -lsa $(which python) will let you see if it is a symlink to another location or a real executable. if a Symlink you can see where it points to and so you can follow the breadcrumbs to the final binary used.
if you run python from a terminal and in the python REPL do the following
import sys
print sys.path
you can see to which site-packages locations are pointed.
Other than that you of course have the option to use virtual environments to set up your version of python
if you really want python2 to be the default python command you can add a symlink to your ~/bin folder (create it if it does not exist)
mkdir ~/bin
cd ~/bin
ln -s $(which python2) python
chmod +x python
and make sure that export PATH=~/bin:$PATH is added at the back of your .bashrc or .profile or .zshrc file
Now start a new terminal session and try out python again it should point to brews version
Hope that helps
I installed both python 2.7.13 and python 3.6.2 with homebrew and updated my ~/.bash_profile as such:
# Homebrew
export PATH=/usr/local/bin:$PATH
Python3 was linked fine. However, "which python" would still give me
/usr/bin/python
while "which python2" produces
/usr/local/bin/python2
It looks like homebrew installed python 2 as "python2" and never linked "python" to the new installation. This is causing me a lot of trouble down the road when installing virtualenvwrapper etc.
By the way, I also did
brew link python.
Anybody know why this is and how to fix it?
Much appreciated!!
They change that behavior here
Today I’d like to announce Homebrew 1.3.0. The most significant change
since 1.2.0 is that brew install python no longer installs a python
binary without manual PATH additions and instead installs a python2
binary. This avoids overriding the system python binary by default
when installing Python as a dependency. It also paves the way to
eventually have python be Python 3.x.
You will have to symlink python to the version of python installed by homebrew that you want.
You can do:
$ln -s /usr/local/bin/python2 /usr/local/bin/python
To symlink python to the homebrew Python2.x installation or do:
$ln -s /usr/local/bin/python3 /usr/local/bin/python
to link it to the Python 3.x hombrew installation.
gsi-frank's solution solves the problem quite well but after using his solution, you might encounter problems with your pip3. Your pip3 might be linked to the old instance and therefore unusable for your new python instance.
Type which pip3 to see where your pip3's path.
If your path is linked to your new instance, then ignore the rest of this answer.
Type echo $PATH to see your current path. If it contains your old python instance's path then you will need to remove it from your .bash_profile
To solve this: check your .bash_profile and see if there is a path to your old python instance.
If the old path is in there, you can delete it.
I had this problem and here's a link to the question if needed:
How to change pip3 path after installing python with homebrew?
To find your .bash_profile:
Go to your Finder
Right click and click Go to a folder... and type ~
Press CMD + shift + . to see hidden files
Right click your .bash_profile and open in a text editor
I am trying to find out why my virtualenv and/or virtualenv wrapper - installed using pip using homebrew - cannot be found. I think it's because it's not added to my PATH:
$ which virtualenv
$
and:
$ virtualenv someDir
$ -bash: virtualenv: command not found
I installed pip using homebrew, and virtualenv using pip, without problems. I tried reinstalling virtualenv, but that did not work either.
How do I know what path to add to PATH? Just the path that virtualenv.py seems to be installed into? That seems to be:
/usr/local/lib/python2.7/site-packages/virtualenv.py
I also found this guide, which suggests this:
$ ln -s ../Cellar/python/2.7/Frameworks/Python.framework/Versions/2.7/bin/virtualenv virtualenv
However, it does not help me run virtualenv. I am on Mac OSX 10.7.5 (Lion).
It seems that I myself am the exception to the rule for almost all 'simple' installation procedures. For some reason, it WAS a path related issue:
I ran brew info python, which outputted a lot of information. At the bottom I found this:
Executable python scripts will be put in:
/usr/local/share/python
so you may want to put "/usr/local/share/python" in your PATH, too.
I added that to my PATH in /etc/launchd.conf and ~/.bashrc and lo and behold:
$ which virtualenv
tells me:
"/usr/local/share/python/virtualenv"
I still don't know why I couldn't find any pointers in the right direction, online, anywhere? Is pip install virtualenv supposed to add to the PATH itself? If so, why not on my system? Why did #bibhas tell me explicitly it was not a path issue?
Had the same issue after pip install virtualenv
When I inspected python ls -la /usr/local/bin/python I found it was symbolically linked to /Library/Frameworks/Python.framework/Versions/2.7/bin/python
When I cd in that directory I also found the virtualenv executable and
Fixed it by
cd /Library/Frameworks/Python.framework/Versions/2.7/bin
ln virtualenv /usr/local/bin/virtualenv
Sidenote: I also happen to have a python installation in /System/Library/Frameworks/Python.framework/Versions/2.7/bin
I believe that's the one that came with OSX
In your .bashrc you need to have:
export WORKON_HOME=~/.virtualenvs
source /usr/local/bin/virtualenvwrapper.sh
(Mac / Linux specific)
So I got an error message when I did a pip3 install --user --upgrade virtualenv telling me that I did not have Users/home/Library/Python/3.7/bin in my PATH. So I simply added it.
If this is on the Mac, the following did it for me
vi ~/.bash_profile
PATH="/Users/home/Library/Python/3.7/bin:/Library/Frameworks/Python.framework/Versions/3.7/bin:${PATH}"
restart your terminal and type virtualenv env and that should do it.
I solved it by:
At first, I found out it is located at /usr/local/python3
and then I fixed it by the command:
ln virtualenv /usr/local/bin/virtualenv
This solution will give you an alternate tool to use and solve your virtualenv problem at the same time.
Use pythonbrew. It is inspired from rvm in the ruby world and is helpful in managing pythons on your system and also wrap virtualenv commands to provide virtual environment management. I use it Mountain Lion for my development purposes and have had no problems. More details (on my blog): http://stacktoheap.com/blog/2013/03/11/why-use-virtualenv-when-there-is-pythonbrew/
My idea is to add your virtualenv position to the BASH PATH
export PATH=$PATH:/usr/local/python2.7/bin
Or change your position
For those with Python 2.7, I came across this as well, and solved it by simply putting the following line into the \etc\paths file (may need to $ sudo chmod it first):
/Library/Frameworks/Python.framework/Versions/2.7/bin
Save the change and start a new Terminal session. Check it with echo $PATH
The module in /usr/local/lib/python2.7/site-packages is imported by a short script that uses pkg_resources.load_entry_point to run the application. The utility script should be in /usr/local/bin.
I try to switch to Homebrew (after using fink and macport) on Mac OS X 10.6.2. I have installed python 2.7 with
brew install python
The problem is that, contrary to Macport, it seems that there is no python_select utility, and my default mac python is always default
which python
give me
/usr/bin/python
and /usr/bin/python is not a symlink
How can I do to make python brew flavour to be my default python ?
As suggested by the homebrew installer itself, be sure to add this to your .bashrc or .zshrc:
export PATH="/usr/local/opt/python/libexec/bin:$PATH"
As you are using Homebrew the following command gives a better picture:
brew doctor
Output:
==> /usr/bin occurs before /usr/local/bin This means that system-provided programs will be used instead of those provided by
Homebrew. This is an issue if you eg. brew installed Python.
Consider editing your .bash_profile to put: /usr/local/bin ahead of
/usr/bin in your $PATH.
See: How to symlink python in Homebrew?
$ brew link --overwrite python
Linking /usr/local/Cellar/python/2.7.3... 28 symlinks created
$ which python
/usr/local/bin/python
Quick fix:
Open /etc/paths
Change the order of the lines (highest priority on top)
In my case /etc/paths looks like:
/usr/local/bin
/usr/local/sbin
/usr/bin
/bin
/usr/sbin
/sbin
If you want to know more about paths in OSX I found this article quite useful:
http://muttsnutts.github.com/blog/2011/09/12/manage-path-on-mac-os-x-lion/
I did "brew install python" for OSX High Sierra. The $PATH had /usr/local/bin before any other path but still which python was pointing to the system's python.
When I looked deeper I found that there is no python executable at /usr/local/bin. The executable is named python2. To fix this problem create a symbolic link python pointing to python2:
/usr/local/bin $: ln -s python2 python
For Apple Silicon machines, the path are slightly different. After running brew install python, you must ensure your ~/.zshrc uses the correct Homebrew paths:
# Homebrew
eval "$(/opt/homebrew/bin/brew shellenv)"
# Homebrew: Python
export PATH="/opt/homebrew/opt/python/libexec/bin:$PATH"
Results:
% which python
/opt/homebrew/opt/python/libexec/bin/python
% python --version
Python 3.9.9
% which pip
/opt/homebrew/opt/python/libexec/bin/pip
% pip -V
pip 21.3.1 from /opt/homebrew/lib/python3.9/site-packages/pip (python 3.9)
python formula now uses python3(v3.6.5 for now), brew will link the directory:
/usr/local/opt/python -> ../Cellar/python/3.6.5
it will also link the binary:
/usr/local/bin/python3 -> ../Cellar/python/3.6.5/bin/python3
If you still need to use python2.x, use:
brew install python#2
To use homebrew's python, just put its directory in PATH, for bash:
export PATH="/usr/local/opt/python/libexec/bin:$PATH"
for fish:
set -x PATH /usr/local/opt/python/libexec/bin $PATH
Note:
doing this will shadow the system default version of python
homebrew used to link python to /usr/local/share/python in older versions.
Homebrew does NOT replace stuff in "/usr/bin". You'll just want to put "/usr/local/bin" ahead of "/usr/bin" in your path, then "which python" will give you "/usr/local/bin/python".
Replacing /usr/bin/python (or /usr/bin/ruby) is highly unrecommended.
Modify your $PATH, Add this in your bashrc or bash_profile:
export PATH=/usr/local/bin:/usr/local/sbin:~/bin:$PATH
more click here:
Issue #89791
I did brew install python, my $PATH was good, but still, which python gave me the system installed one. Restarting the terminal fixed it.
You need to edit your PATH environmental variable to make sure wherever the homebrew python is located is searched before /usr/bin. You could also set things up in your shell config to have a variable like PYTHON be set to your desired version of python and call $PYTHON rather than python from the command line.
Also, as another poster stated (and especially on mac) DO NOT mess with the python in /usr/bin to point it to another python install. You're just asking for trouble if you do.
python now points to python3, if you need python 2 then do:
brew install python#2 and then in your .zshrc or .bashrc file
export PATH="/usr/local/opt/python#2/libexec/bin:$PATH"
Now, pyhon --version = Python 2.7.14 and python3 --version = Python 3.6.4.
That's the behavior I'm used to seeing in my terminal.
I believe there are means to make homebrew python default, but in my opinion the proper way to solve a problem is not to mess with system python paths: it is better to create a virtualenv in which homebrew python would be default (by using virtualenv --python option). Using tools like python_select is almost always a bad idea.
Use pyenv instead to install and switch between versions of Python. I've been using rbenv for years which does the same thing, but for Ruby. Before that it was hell managing versions.
Consult pyenv's github page for installation instructions. Basically it goes like this:
- Install pyenv using homebrew. brew install pyenv
- Add a function to the end of your shell startup script so pyenv can do it's magic. echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n eval "$(pyenv init -)"\nfi' >> ~/.bash_profile
Use pyenv to install however many different versions of Python you need. pyenv install 3.7.7.
Set the default (global) version to a modern version you just installed. pyenv global 3.7.7.
If you work on a project that needs to use a different version of python, look into pyevn local. This creates a file in your project's folder that specifies the python version. Pyenv will look override the global python version with the version in that file.
Add the /usr/local/opt/python/libexec/bin explicitly to your .bash_profile:
export PATH="/usr/local/opt/python/libexec/bin:$PATH"
After that, it should work correctly.
Just do:
brew install python
brew link python
After doing that, add this to your bashrc or bash_profile:
alias python='/usr/local/bin/python2'
Enjoy!
You can edit /etc/paths. Here is mine:
/usr/local/bin
/usr/bin
/bin
/usr/sbin
/sbin
Then add a symlink for the python version. In my case
$ cd /usr/local/bin
$ ln -s python3 python
Voila!
If you are fish shell
echo 'set -g fish_user_paths "/usr/local/opt/python/libexec/bin" $fish_user_paths' >> ~/.config/fish/config.fish
try this
which python3
Try typing python3 instead of just python
Greeting folks! I have the need to use python 3.10 version to harness its new features. My solved solution at 2022-07-03 is as follows. Have fun coding python!
» rm '/usr/local/bin/pip3.10'
» brew link python#3.10
» echo 'export PATH="/usr/local/opt/python#3.10/bin:$PATH"' >> ~/.zshrc
» python3
Python 3.10.5 (main, Jun 23 2022, 17:15:25) [Clang 13.1.6 (clang-1316.0.21.2.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
Since High Sierra, you need to use:
sudo chown -R $(whoami) $(brew --prefix)/*
This is because /usr/local can no longer be chowned
brew link python
And you must create/add an alias for python and put it in your .zprofile (Located in Users/username folder, if you press Shift+command+.
This must point to your homebrew python installation location.
alias python ='opt/homebrew/bin/python3'
No idea what you mean with default Python. I consider it bad practice to replace the system Python interpreter with a different version. System functionality may depend in some way on the system Python and specific modules or a specific Python version. Instead install your custom Python installations in a safe different place and adjust your $PATH as needed in order to call you Python through a path lookup instead of looking for the default Python.