Menu
Yesterday I upgraded pyenv via brew from 1.2.24.1 -> 2.0.3. Since that time now when I open any new terminal window, python is linked to the built in system Python 2 instead of my global pyenv python.
If I do a pyenv virtualenvwrapper in a terminal window, and then create and activate a virtual environment (mkvirtualenv foobar and workon foobar) then my global pyenv Python is activated correctly. Ex:
$ pyenv global
3.9.6
$ which python
/usr/bin/python
$ python
WARNING: Python 2.7 is not recommended.
This version is included in macOS for compatibility with legacy software.
Future versions of macOS will not include Python 2.7.
Instead, it is recommended that you transition to using 'python3' from within Terminal.
Python 2.7.16 (default, Mar 25 2021, 03:11:28)
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>
$ pyenv virtualenvwrapper
$ mkvirtualenv foobar
created virtual environment CPython3.9.6.final.0-64 in 346ms
creator CPython3Posix(dest=/Users/adam.parkin/.envs/foobar, clear=False, no_vcs_ignore=False, global=False)
seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=/Users/adam.parkin/Library/Application Support/virtualenv)
added seed packages: pip==21.1.3, setuptools==57.1.0, wheel==0.36.2
activators BashActivator,CShellActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator
virtualenvwrapper.user_scripts creating /Users/adam.parkin/.envs/foobar/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/adam.parkin/.envs/foobar/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/adam.parkin/.envs/foobar/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/adam.parkin/.envs/foobar/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/adam.parkin/.envs/foobar/bin/get_env_details
$ workon foobar
$ python
Python 3.9.6 (default, Jul 19 2021, 19:04:48)
[Clang 12.0.0 (clang-1200.0.32.29)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>
But I don't understand why a new fresh terminal isn't using the Pyenv python instead of the system default python?
My path seems to be pointing to the shims directory before /usr/bin, yet a which python is pointing to /usr/bin/python. My path:
$ echo $PATH
/usr/local/Cellar/pyenv-virtualenv/1.1.5/shims:/Users/adam.parkin/.pyenv/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/adam.parkin/.local/bin:/Users/adam.parkin/bin
As you can see I have the pyenv-virtualenv plugin installed.
The output from the brew upgrade pyenv command when I upgraded can be found in this gist: https://gist.github.com/pzelnip/ca99bf955fe15f66225a41f597501dff
My .bashrc contains the following lines related to pyenv (these are the last 3 lines of my bashrc):
export PATH="$HOME/.pyenv/bin:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"
If I do a PYENV_DEBUG=1 pyenv init -, the output can be seen in this gist: https://gist.github.com/pzelnip/641a862c19f35571c20fb7d2cb1aabe8
923
Meet pyenv: a Simple Python Version Management tool. Previously known as Pythonbrew, pyenv lets you change the global Python version, install multiple Python versions, set directory (project)-specific Python versions, and yes create/manage virtual python environments ("virualenv's").
Shims are lightweight executables that simply pass your command along to pyenv. So with pyenv installed, when you run, say, pip , your operating system will do the following: Search your PATH for an executable file named pip. Find the pyenv shim named pip at the beginning of your PATH.
Even if you already have Python installed on your system, it is worth having pyenv installed so that you can easily try out new language features or help contribute to a project that is on a different version of Python. Why Not Use System Python? “System Python” is the Python that comes installed on your operating system.
In order to use the version of Python through pyenv, it's essential to understand the shell's PATH variable. PATH determines where the shell searches for files by the name of the command. You must ensure the shell will find the version of Python run by pyenv, not the one installed by default (which is often called the system version).
If you haven’t heard of virtual environments before, you can check out Python Virtual Environments: A Primer. Virtual environments and pyenv are a match made in heaven. pyenv has a wonderful plugin called pyenv-virtualenv that makes working with multiple Python version and multiple virtual environments a breeze.
This command activates the version specified by setting the PYENV_VERSION environment variable. This command overwrites any applications or global settings you may have. If you want to deactivate the version, you can use the --unset flag.
Change eval "$(pyenv init -)" to eval "$(pyenv init --path)" and start a new shell.
Seems like this was a change that was introduced in 2.0
122
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
