I have both python3.6 and 3.7 and multiple other versions installed. Currently the default is 3.6, yet I need to switch it to 3.7, otherwise it will throw error with some libraries, such as this https://github.com/pytorch/pytorch/issues/17237 'Symbol not found: _PySlice_Unpack'.
I tried a few methods such as
ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python.
I also added this line to bash_profile #export PATH=$PATH:$HOME/Library/Python/3.7/bin
However when I run python -V in terminal it's still python3.6.0. While this looks simple, what's the proper way to fix it?
Related
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
I am installing Python 3.7.2 for the first time, and I'm using the VS Code python extension.
When I run python -V I get Python 2.7.10 which is not correct!
When I select the usr/local/bin/python3 interpreter in VS Code I get this error when running a script:
bash: /Users/erik/Work/Python/usr/local/bin/python3: No such file or directory
But when I look in usr/local/bin I can see that Python3 is there. I'm not sure why VS Code pastes the work directory in front of usr/local/bin ?
My first thought was that Python3 should be in the PATH variable so I ran the included Update Shell Profile command, which gives this feedback:
This script will update your shell profile when
the 'bin' directory of python is not early enough
of the PATH of your shell.
All right, you're a python lover already
Now, after rebooting VS Code I get a new option for selecting an interpreter:
/Library/Frameworks/Python.framework/Versions/3.7/bin/python3
Is that different from the Python in usr/local/bin ? When I select it, I get this error:
The script isort is installed in '/Users/erik/Library/Python/3.7/bin' which is not on PATH.
I also get this sideways related error:
You are using pip version 18.1. You should consider upgrading via the 'pip install --upgrade pip' command.
But, when following these instructions I get yet another error:
bash: pip: command not found
All in all, this process and the official documentation seem less than user-friendly? Apparently I'm required to dig deep through my mac's system files in the terminal before even writing one line of code.
Am I missing an essential step here?
I suggest that you use virtual environment for your project
first
pip install virtualenv
open cmd in your project directory that you open in VS-Code (it's important that vs-code sees this virtualenv folder that we will create)
mkvirtualenv my_env
and it will activate it automatically. if not run
my_env/bin/Scripts/activate or my_env/Scripts/activate
Then go open vs-code then select my_env for python interpreter
Well, if you want to change your default Python version for the whole system, it might break some applications that are depending on Python 2.
You can alias the commands by adding this line to your ~/.bash_profile:
$ alias python='python3'
The python command will now refer to python3.
If you want to execute the original Python (which refers to python2), you can escape the alias (so \python will launch python2 without touching the alias).
Btw.
$ unlink /usr/local/bin/python
$ ln -s /usr/local/bin/python3.7 /usr/local/bin/python
could also be a workaround for you.
I am trying to run python3.6.8 in cygwin.
Typing python -v just results in the terminal window hanging. I have to escape out of it to make it respond further.
Typing python36 -v results in the error python36 command not found. I definitely installed this module while installing Cygwin.
I notice in /cygdrive/c, only python27 seems to be present. Running python -i also shows me that 2.7 is installed.
I want to run 3.6.8, have tried reinstalling multiple times, same issue.
Running "which python" shows only
/cygdrive/c/Python27/python
How can I troubleshoot this?
Generally all the python versions with 3 can be accessed using python3 as binary. In windows often the path variable doesn't hold the python3 binary path so the binary is not called.
do
echo $PATH | grep python
Check for the version of the python if python36 is present then do
python3 --version
Look in /usr/bin for all python exe's. Use ls -l /usr/bin/python*.*. I suspect you will not find python3.6m.exe.
Run cygwin setup again and select the python3.6 package. You can also install a version of 3.7, 3.8 or some older ones if you wish. You can only get the latest release of the e.g. 3.6 series.
What I'm trying to do here is to make python3 as my default python. Except the python 2.7 which automatically installed on mac, I installed python3 with homebrew. This is the website that I'm following. http://docs.python-guide.org/en/latest/starting/install3/osx/#install3-osx
I guess I followed every instruction well, got xcode freshly installed, Command line tools, and homebrew. But here's my little confusion occurs.
The script will explain what changes it will make and prompt you before the installation begins. Once you’ve installed Homebrew, insert the Homebrew directory at the top of your PATH environment variable. You can do this by adding the following line at the bottom of your ~/.profile file
export PATH=/usr/local/bin:/usr/local/sbin:$PATH
I was really confused what this was, but I concluded that I should just add this following line at the bottom of ~/.profile file. So I opened the ~/.profile file by open .profile in the terminal, and added following line at the bottom. And now it looks like this.
export PATH=/usr/local/bin:/usr/local/sbin:$PATH
# Setting PATH for Python 3.6
# The original version is saved in .profile.pysave
export PATH=/usr/local/bin:/usr/local/sbin:$PATH
And then I did brew install python, and was hoping to see python3 when I do python --version.
But it just shows me python 2.7.10. I want my default python to be python3 not 2.7
And I found a little clue from the website.
Do I have a Python 3 installed?
$ python --version
Python 3.6.4
If you still see 2.7 ensure in PATH /usr/local/bin/ takes pecedence over /usr/bin/
Maybe it has to do something with PATH? Could someone explain in simple English what PATH exactly is and how I could make my default python to be python3 when I run python --version in the terminal?
Probably the safest and easy way is to use brew and then just modify your PATH:
First update brew:
brew update
Next install python:
brew install python
That will install and symlink python3 to python, for more details do:
brew info python
Look for the Caveats:
==> Caveats
Python has been installed as
/usr/local/bin/python3
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
Then add to your path /usr/local/opt/python/libexec/bin:
export PATH=/usr/local/opt/python/libexec/bin:$PATH
The order of the PATH is important, by putting first the /usr/local/opt/python/libexec/bin will help to give preference to the brew install (python3) than the one is in your system located in /usr/bin/python
Before we make the changes, the default version of python in my system was python 2.7.17.
python --version
Python 2.7.17
To make python3 as default python by replacing python2 in Ubuntu.
Open Terminal
cd
nano ~/.bashrc
alias python=python3 (Add this line on top of .bashrc file)
Press ctr+o (To save the file)
Press Enter
Press ctr+x (To exit the file)
source ~/.bashrc OR . ~/.bashrc (To refresh the bashrc file)
python --version
Python 3.7.5
Changing the default python version system wide can break some applications that depend on python2. The alternative solution would be to create an alias.
If you are using zsh (the default on Mac OS) run the following from terminal:
echo 'alias python="python3"' >> ~/.zshrc
echo 'alias pip="pip3"' >> ~/.zshrc
According to this S.O. post, changing the default Python interpreter could possibly break some applications that depend on Python 2.
The post also refers to using aliasing as a solution, and this link might also be a good reference on how to do that.
Personally, I just type "Python3" before I run scripts or go into a shell environment instead of "python".
I have a mac, when I do:
python --version
I got:
Python 2.7.6
but when I got to:
/System/Library/Frameworks/Python.framework/Versions/3.3
where is 2.7.6 located ?
any advice what should I do?
UPDATE:
$ which -a python python3
/usr/bin/python
/usr/local/bin/python3
$ brew list python python3
Error: No such keg: /usr/local/Cellar/python
$ locate python
WARNING: The locate database (/var/db/locate.database) does not exist.
To create the database, run the following command:
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist
Please be aware that the database can take some time to generate; once
the database has been created, this message will no longer appear.
in PyCharm editor, the default settings interpreter shows:
You could have multiple Python versions on your macOS.
You may check that by command, type or which command, like:
which -a python python2 python2.7 python3 python3.6
Or type python in Terminal and hit Tab few times for auto completion, which is equivalent to:
compgen -c python
By default python/pip commands points to the first binary found in PATH environment variable depending what's actually installed. So before installing Python packages with Homebrew, the default Python is installed in /usr/bin which is shipped with your macOS (e.g. Python 2.7.10 on High Sierra). Any versions found in /usr/local (such as /usr/local/bin) are provided by external packages.
It is generally advised, that when working with multiple versions, for Python 2 you may use python2/pip2 command, respectively for Python 3 you can use python3/pip3, but it depends on your configuration which commands are available.
It is also worth to mention, that since release of Homebrew 1.5.0+ (on 19 January 2018), the python formula has been upgraded to Python 3.x and a python#2 formula will be added for installing Python 2.7. Before, python formula was pointing to Python 2.
For instance, if you've installed different version via Homebrew, try the following command:
brew list python python3
or:
brew list | grep ^python
it'll show you all Python files installed with the package.
Alternatively you may use apropos or locate python command to locate more Python related files.
To check any environment variables related to Python, run:
env | grep ^PYTHON
To address your issues:
Error: No such keg: /usr/local/Cellar/python
Means you don't have Python installed via Homebrew. However double check by specifying only one package at a time (like brew list python python2 python3).
The locate database (/var/db/locate.database) does not exist.
Follow the advice and run:
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist
After the database is rebuild, you can use locate command.
To check third version, we can use,
python3 --version
To install python on macOS, we need to install command line developer tools. From Catalina, python is removed from OS bundle. For more information, Apple Official and Python Official.
Use below command to see all python installations :
which -a python
Use the which command. It will show you the path
which python
Take a look at the docs regarding Python on Mac.
The version at /System/Library/Frameworks/Python.framework is installed by Apple and is used by the system. It is version 3.3 in your case. You can access and use this Python interpreter, but you shouldn't try to remove it, and it may not be the one that comes up when you type "Python" in a terminal or click on an icon to launch it.
You must have installed another version of Python (2.7) on your own at some point, and now that is the one that is launched by default.
As other answers have pointed out, you can use the command which python on your terminal to find the path to this other installation.
You can use python official installer. It's very easy and interactive.
Refer https://www.python.org/downloads/release/python-2716/
Just type python and then hit tab-button You will get the list of all the python available in your os