====== Multiple python versions ======


====== pyenv ======

  * [[https://realpython.com/intro-to-pyenv/]]
  * [[https://askubuntu.com/questions/682869/how-do-i-install-a-different-python-version-using-apt-get]]

===== Installation =====

For fully automated installation: <code bash>curl https://pyenv.run | bash</code>

Manual installation steps:

<code bash>
git clone https://github.com/pyenv/pyenv.git ~/.pyenv

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc

# Restart shell to apply new PATH variable
exec "$SHELL"
</code>

==== Install plugins ====

<code bash>
git clone https://github.com/pyenv/pyenv-update.git $(pyenv root)/plugins/pyenv-update
git clone https://github.com/pyenv/pyenv-virtualenv.git $(pyenv root)/plugins/pyenv-virtualenv

</code>


===== Install Python build dependencies =====
<code bash>
sudo apt update; sudo apt install build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev curl \
libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
</code>

===== Install additional Pythons =====

<code bash>

# list of all available versions
pyenv install -l

pyenv install 3.11
</code>

===== Usage =====

<code bash>
$ python3 --version
Python 3.9.2

$ pyenv global 3.11

$ python3 --version
Python 3.11.4

$ pyenv global system

$ python3 --version
Python 3.9.2
</code>