I've just installed Python version 3.11 (I also moved versions 3.8 and 3.9 to the trash from my Applications folder).
I can see it in the following:
$ myname#name-MBP miniconda3 % ls /usr/local/bin/py*
/usr/local/bin/pydoc3 /usr/local/bin/python3-intel64
/usr/local/bin/pydoc3.11 /usr/local/bin/python3.11
/usr/local/bin/python3 /usr/local/bin/python3.11-config
/usr/local/bin/python3-config /usr/local/bin/python3.11-intel64
(Any additional recommendations on whether I need to clean things up would be much appreciated.)
Checking python3 --version still displays Python 3.8.13.
First attempt to solve
Initially I tried installing it from the command line using homebrew and specifying the version:
brew install python#3.11
I also tried using conda, but neither of these worked.
Second attempt to solve
My initial thought was to check my PATH (I think this is how Python decides which version to use, but please correct me if I'm wrong).
This still only contained version 8 paths:
/Users/myname/miniconda3/lib/python38.zip
/Users/myname/miniconda3/lib/python3.8
/Users/myname/miniconda3/lib/python3.8/lib-dynload
/Users/myname/.local/lib/python3.8/site-packages
/Users/myname/miniconda3/lib/python3.8/site-packages
So I added the Python3.11 path to it using
PYTHONPATH="/usr/local/bin/pydoc3.11/:$PYTHONPATH"
export PYTHONPATH
Now it includes the v3.11 path when I print out sys.path:
/usr/local/bin/python3.11
/usr/local/bin/pydoc3.11
/Users/myname/miniconda3
/Users/myname/miniconda3/lib/python38.zip
/Users/myname/miniconda3/lib/python3.8
/Users/myname/miniconda3/lib/python3.8/lib-dynload
/Users/myname/.local/lib/python3.8/site-packages
/Users/myname/miniconda3/lib/python3.8/site-packages
But the python3 --version output is still unchanged.
Questions
I'm nervous to keep playing around with the contents of my path and entering random command line executions to try to solve this because I really have no clue what I'm doing.
What's happening here?
How can I get the output of python3 --version to be 3.11?
So first thing to understand is setting the variable PYTHONPATH will not affect which version of python is executed by the shell. The shell (bash/zsh) only knows to scan the paths in the PATH env var to figure out all the executables.
Now there are two ways to solve this.
1. Using the python#3.11 from homebrew.
There are several downsides to using this method. Currently, the default python3 by brew is 3.10.x. Whenever you will install any cask or formula that depends on python#3, it'll invariably install the python#3 formula aka 3.10.x. Installing python3 will make brew symlink 3.10.x into /opt/homebrew/bin.
Python 3.11.x can be used by installing python#3.11 and invoking python3.11. This should drop you into the Python 3.11 interpreter. Append all python executable names with the version like pip will be pip3.11
Trying to force 3.11 over 3.10 links will be complicated and cause instability. It'll only cause frustration during development.
2. Using VirtualEnvs
Your best bet for the most stable and no-headache approach to python is to create virtual envs using either venv or pyenv. use pyenv-virtualenv for max ease of use.
One limitation of venv is that it'll create a virtualenv of the same version that invoked it. Aka if you do brew install python#3 && python3 -m venv <folder>, it'll create virtualenv of python3. For 3.11 you'll have to brew install python#3.11 && python3.11 -m venv <folder>. Pyenv on the other hand can install any version of python.
Go through https://www.dataquest.io/blog/a-complete-guide-to-python-virtual-environments/ and https://github.com/pyenv/pyenv-virtualenv to understand and learn more.
Suddenly I cannot run ansible.
Whenever I try any ansible command like ansible-playbook, ansible version, etc. it shows error
`/Users/myusername/Library/Python/2.7/bin/ansible: /System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/: bad interpreter: No such file or directory`,
Even if I let ansible run different python version, like ansible-playbook --version -e 'ansible_python_interpreter=/usr/bin/python3, it shows the same error.
FYI: which ansible returns /Users/myusername/Library/Python/2.7/bin/ansible
I guess it is related to my recent installation of python. Since I installed a python3.10 recently, The python2.7 becomes not work. Note I did not remove anything about python2.7 myself. looks like the installation of python3.10 changed python2.7 setting.
For most other application, I now pointed the system to use python3 as workaround, e.g. I set CLOUDSDK_PYTHON=/usr/bin/python3 to make accessing cloud cli works again. But for Ansible, I have not figured out how to make it work. I am using MacOS terminal.
Does anybody know how to resolve the above issue so that I can run ansible again? Anyway is OK as long as I can run ansible. Either reinstall ansible and let it use python3 instead of using Python2.7 or guide me how to reinstall python2.7 (in a right way, not messy with python3.10, currently I am scared of installing python, I am afraid if I reinstall python2.7, both python3.10 and 2.7 will be out of work then I cannot work).
Please help. Thanks.
You will have to do some cleanup on your system because somehow, Python 2.7 was removed from you system. This might have happened due to updating to macos 12.4 Monterey at some point, because Monterey 12.3 and newer removed the system-provided Python 2.7, replacing it with a Python 3.8.9 installation (/usr/bin/python3).
However, you still have stuff in your environment that reference all those Python 2.7 things, like your ${HOME}/Library/Python/2.7/bin/ansible directory.
Here are the things you can do to (hopefully) make ansible and your environment work again.
Change your shell's PATH environment.
You're probably using zsh since it's the default shell on macos. Have you ever changed your .zshrc or other environment files to add /Users/<name>/Library/Python/2.7/bin in your PATH? You will need to remove that.
Additionally, if you strictly want to use the Python 3.10 you manually installed (and not Monterey's system-provided /usr/bin/python3 which is python v3.8.9), you will probably need a PATH that looks like this...
# somewhere in your ~/.zshrc, probably near the bottom
export PATH="/Library/Frameworks/Python.framework/Versions/3.10/bin:${PATH}"
Re-install Ansible
With whatever python3 binary you're using, re-install ansible
python3 -m pip install --user ansible
This will end up installing ansible into ${HOME}/Library/Python/<VERSION>/bin
Update PATH again to include new bin dir
Building on part (1) above, you want to include the bin directory for Python stuff in your user directory, to be able to refer to anything installed by pip install --user.
# somewhere in your ~/.zshrc, probably near the bottom
export PATH="${HOME}/Library/Python/3.10/bin:${PATH}"
export PATH="/Library/Frameworks/Python.framework/Versions/3.10/bin:${PATH}"
Reload your shell and try to run ansible
# if you already have a shell open, run this
# to reload your zsh configs
exec zsh
# hopefully this returns the correct path!
which ansible
# and hopefully this runs!
ansible --help
Reinstall Anything Else You Need
You reference stuff like CLOUDSDK_PYTHON which sounds like you also have stuff like the gcloud module installed. Time to reinstall those with your new Python.
python3 -m pip install --user gcloud
# and whatever else needs reinstalling
Hopefully this all fixes your environment. Now you can clean up the remnants of Python 2.7 stuff from your home directory once everything else is working, as this directory has broken module installs that reference a deleted system Python anyway.
cd ~/Library/Python
rm -rf 2.7
Just recently upgraded to Mac OSX Catalina, and it seems to have broken all my Python venv's.
I have a venv that I previously created before upgrading to Catalina.
I can activate the venv without issue: source venv/bin/activate
When I type python or python3, it actually runs the system Python interpreters, instead of the expected Python interpreter in my venv.
With my venv activated...
>>> which python
/usr/bin/python
>>> which python3
/usr/local/bin/python3
I expect that to point to /Users/<username>/<path-to-venv>/venv/bin/python3.
If I try to run that Python interpreter directly:
>>> /Users/<username>/<path-to-venv>/venv/bin/python3
bash: /Users/<username>/<path-to-venv>/venv/bin/python3: No such file or directory
If I navigate to this venv directory in Finder, I can see that the python3 file exists, although it's actually an alias. If I double-click on it, I get an error message that pops up that reads: The operation can't be completed because the original item for "Python3" can't be found.
So I think the way these venv's work is that they are based on references to existing Python interpreter installations. Evidently running a venv invokes these references, and if the original installation is broken it fails. I know that Catalina jacked with the default Python settings and went so far as to change installation directories.
Has anyone else encountered this? Can anyone offer tips to fix this? This seems to affect all my venv virtual environments across my system.
You can try to create a new venv in the same folder or to update your existing venv. With all the following I assume you've created your virtual environments with the bundled venv module
For the creation it's the command you've probably already used
python3 -m venv <path_to_dir>
In order to update, the --upgrade parameter is what you're looking for.
You need to run it with the targeted Python version, for example in this case:
python3 -m venv --upgrade <path_to_dir>
for more details, see my answer here
After moving over to Fedora (from Windows), I realized that it came with both installations of Python 2.7.5 and Python 3.6.6.
As I familiarized myself with using Python, I learned of the great utilities of virtual environments and how organized they keep everything.
However, my current dilemma is for which Python version should I do pip(2 or 3) install virtualenv virtualenvwrapper.
From my research, I understand that the virtualenvwrapper provides the ability to create a virtual environment using a specified version of Python: mkvirtualenv -p /usr/bin/python(2 or 3) {name}.
Therefore, should I only install virtualenv and virtualenvwrapper on one of the Python versions and use the aforementioned feature? Or should I install virtualenv and virtualenvwrapper on both versions of Python.
Would there be any conflicts?
Edit
More importantly, assuming that I have virtualenv and virtualenvwrapper installed for both Python 2.7.5 and Python 3.6.6, which version's command is called when I run any of the following: workon, mkvirtualenv, rmvirtualenv, etc.?
Would there be any conflicts?
Not until you mistakenly run the default system python command with a script that's using the opposite version as compared to the more specific python2 or python3 commands.
The virtualenvs do not conflict, and must be activated to be used. You can also of course have as many virtualenv's as you wish.
To avoid any problems setting up an environment, its suggested to run python2 -m virtualenv for example, rather than simply virtualenv command itself
For the commands listed at the bottom of the question, it depends on how your PATH is configured. Personally, I use pyenv rather than virtualenv directly, which injects itself into the OS PATH variable
I've installed virtualenv via pip and get this error after creating a new environment:
selenium:~ auser$ virtualenv new
New python executable in new/bin/python
ERROR: The executable new/bin/python is not functioning
ERROR: It thinks sys.prefix is u'/System/Library/Frameworks/Python.framework/ Versions/2.6' (should be '/Users/user/new')
ERROR: virtualenv is not compatible with this system or executable
In my environment:
PYTHONPATH=/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages
PATH=/System/Library/Frameworks/Python.framework/Versions/2.6/bin:/Library/Frameworks/Python.framework/Versions/2.6/bin:/Library/Frameworks/Python.framework/Versions/2.6/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
How can I repair this?
Thanks.
Just in case there's someone still seeking for the answer.
I ran into this same problem just today and realized since I already have Anaconda installed, I should not have used pip install virtualenv to install virtual environment as this would give me the error message when trying to initiate it later. Instead, I tried conda install virtualenv then entered virtualenv env_mysite and problem solved.
Like #RyanWilcox mentioned, you might be inadvertently pointing virtualenv to the wrong Python installation. Virtualenv comes with a -p flag to let you specify which interpreter to use.
In my case,
virtualenv test_env
threw the same error as yours, while
virtualenv -p python test_env
worked perfectly.
If you call virtualenv -h, the documentation for the -p flag will tell you which python it thinks it should be using; if it looks wonky, try passing -p python. For reference, I'm on virtualenv 1.11.6.
In case anyone in the future runs into this problem - this is caused by your default Python distribution being conda. Conda has it's own virtual env set up process but if you have the conda distribution of python and still wish to use virtualenv here's how:
Find the other python distribution on your machine: ls -ls /usr/bin/python*
Take note of the availble python version that is not conda and run the code below (note for python 3 and above you have to upgrade virtualenv first): virtualenv -p python2.7(or your python version) flaskapp
I've run across this problem myself. I wrote down the instructions in a README, which I have pasted below....
I have found there are two things that work:
Make sure you're running the latest virtualenv (1.5.1, of this writting)
If you're using a non system Python as your standard Python (which python to check) Forcefully use the System supplied one.
Instead of virtualenv thing use /usr/bin/python2.6 PATH/TO/VIRTUALENV thing (or whatever which
python returned to you - this is what it did for me when I ran into this issue)
I had the same problem and as I see it now, it was caused by a messy Python installation. I have OS X installed for over a year since I bought a new laptop and I have already installed and reinstalled Python for several times using different sources (official binaries, homebrew, official binaries + hand-made adjustments as described here). Don't ask me why I did that, I'm just a miserable newbie believing everything will fix itself after being re-installed.
So, I had a number of different Pythons installed here and there as well as many hardlinks pointing at them inconsistently. Eventually I got sick of all of them and reinstalled OS X carefully cleaned the system from all the Pythons I found using find utility. Also, I have unlinked all the links pointing to whatever Python from everywhere. Then I've installed a fresh Python using homebrew, installed virtualenv and everything works as a charm now.
So, my recipe is:
sudo find / -iname "python*" > python.log
Then analyze this file, remove and unlink everything related to the version of Python you need, reinstall it (I did it with homebrew, maybe official installation will also work) and enjoy. Make sure you unlink everything python-related from /usr/bin and /usr/local/bin as well as remove all the instances of Frameworks/Python.framework/Versions/<Your.Version> in /Library and /System/Library.
It may be a dirty hack, but it worked for me. I prefer not to keep any system-wide Python libraries except pip and virtualenv and create virtual environments for all of my projects, so I do not care about removing the important libraries. If you don't want to remove everything, still try to understand whether your Pythons are, what links point to them and from where. Then think what may cause the problem and fix it.
I ran into a variation of this "not functioning" error.
I was trying to create an environment in a folder that included the path ".../Programming/Developing..." which is actually "/Users/eric/Documents/Programming:Developing/"
and got this error:
ImportError: No module named site
ERROR: The executable env/bin/python2.7 is not functioning
ERROR: It thinks sys.prefix is u'/Users/eric/Documents/Programming:Developing/heroku' (should be u'/Users/eric/Documents/Programming:Developing/heroku/env')
ERROR: virtualenv is not compatible with this system or executable
I tried the same in a different folder and it worked fine, no errors and env/bin has what I expect (activate, etc.).
I got the same problem and I found that it happens when you do not specify the python executable name properly. So for python 2x, for example:
virtualenv --system-site-packages -p python mysite
But for python 3.6 you need to specify the executable name like python3.6
virtualenv --system-site-packages -p python3.6 mysite
On on OSX 10.6.8 leopard, after having "upgraded" to Lion, then downgrading again (ouch - AVOID!), I went through the Wolf Paulus method a few months ago, completely ignorant of python. Deleted python 2.7 altogether and "replaced" it with 3.something. My FTP program stopped working (Fetch) and who knows what else relies on Python 2.7. So at that point I downloaded the latest version of 2.7 from python.org and it's installer got me up and running - until i tried to use virtualenv.
What seems to have worked for me this time was totally deleting Python 2.7 with this code:
sudo rm -R /System/Library/Frameworks/Python.framework/Versions/2.7
removing all the links with this code:
sudo rm /usr/bin/pydoc
sudo rm /usr/bin/python
sudo rm /usr/bin/pythonw
sudo rm /usr/bin/python-config
I had tried to install python with homebrew, but apparently it will not work unless all of XTools is installed, which I have been avoiding, since the version of XTools compatible with 10.6 is ancient and 4GB and mostly all I need is GCC, the compiler, which you can get here.
So I just installed with the latest download from python.org.
Then had to reinstall easy_install, pip, virtualenv.
Definitely wondering when it will be time for a new laptop, but there's a lot to be said for buying fewer pieces of hardware (slave labor, unethical mining, etc).
The above solutions failed for me, but the following worked:
python3 -m venv --without-pip <ENVIRONMENT_NAME>
. <ENVIRONMENT_NAME>/bin/activate
curl https://bootstrap.pypa.io/get-pip.py | python
deactivate
It's hacky, but yes, the core problem really did just seem to be pip.
I did the following steps to get virtualenv working :
Update virtualenv as follows :
==> sudo pip install --upgrade virtualenv
Initialize python3 virtualenv :
==> virtualenv -p python3 venv
I had this same issue, and I can confirm that the problem was with an outdated virtualenv.py file.
It was not necessary to do a whole install --upgrade.
Replacing the virtualenv.py file with the most recent version sufficed.
I also had this problem, and I tried the following method which worked for me:
conda install virtualenv
virtualenv --system-site-packages /anaconda/envs/tensorflow (here envs keeps all the virtual environments made by user)
source /anaconda/envs/tensorflow/bin/activate
Hope it's helpful.
I had this same issue when trying to install py2.7 on a newer system. The root issue was that virtualenv was part of py3.7 and thus was not compatible:
$ virtualenv -p python2.7 env
Running virtualenv with interpreter /usr/local/bin/python2.7
New python executable in /Users/blah/env/bin/python
ERROR: The executable /Users/blah/env/bin/python is not functioning
ERROR: It thinks sys.prefix is u'/Library/Frameworks/Python.framework/Versions/2.7' (should be u'/Users/blah/env')
ERROR: virtualenv is not compatible with this system or executable
$ which virtualenv
/Library/Frameworks/Python.framework/Versions/3.7/bin/virtualenv
# install proper version of virtualenv
$ pip2.7 install virtualenv
$ /Library/Frameworks/Python.framework/Versions/2.7/bin/virtualenv -p python2.7 env
$ . ./env/bin/activate
(env) $
Open terminal and type /Library/Frameworks/Python.framework/Versions/
then type ls /Library/Frameworks/Python.framework/Versions/2.7/bin/
if you are using Python2(or any other else).
Edit ~/.bash_profile and add the following line:
export PATH=$PATH:/Library/Frameworks/Python.framework/Versions/2.7/bin/
cat ~/.bash_profile
In my case the content of ~/.bash_profile is as follows:
export PATH=$PATH:/Library/Frameworks/Python.framework/Versions/2.7/bin/
Now the virtualenv command should work.
If you continue to have trouble with virtualenv, you might try pythonbrew, instead. It's an alternate solution to the same problem. It works more like Ruby's rvm: It builds and creates an entire instance of Python, under $HOME/.pythonbrew, and then sets up some bash functions that allow you to switch easily between versions. Where virtualenv shadows the system version of Python, using symbolic links as part of its solution, pythonbrew builds entirely self-contained installations of Python.
I used virtualenv for years. It's a decent solution, but I've switched to pythonbrew lately. Having completely self-contained Python instances means that installing a new one takes awhile (since pythonbrew actually compiles Python from scratch), but the self-contained nature of each installation appeals to me. And disk is cheap.