What is Pyenv?

When you got multiple python projects at hand that use different python versions, uninstall and reinstall between them makes your python environment a mess.
With pyenv, a Python version management tool, can let developers easily manage, install and switch between python versions.

Installation

pyenv only work on UNIX/MacOS systems, the alternative on Windows is pyenv-win

You can install using homebrew

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brew update
brew install pyenv

Set Up Shell Environment

You should be able to check your shell enviornment with this command: echo $SHELL, then execute the following command accordingly

ZSH
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echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc
echo '[[ -d $PYENV_ROOT/bin ]] && export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc
echo 'eval "$(pyenv init -)"' >> ~/.zshrc

Refer to this for detail setup on fish shell or bash

Restart your shell to let the settings take effect

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exec $SHELL

You can execute pyenv init - to check whether it works, this should output some command-like lines.

Install Python with Pyenv

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# list all available versions
pyenv install -l
# install desire version
pyenv install 3.12.2
# check all versions pyenv has installed
pyenv versions
# check current activate pyenv version
pyenv version

Setting Global and Local Version

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pyenv versions
# output
# * system (set by /Users/user/.pyenv/version)
#   3.9.18
#   3.10.13
pyenv global 3.10.13
# or
pyenv local 3.10.13