Arch Linux 2025.01.01 using Pyenv

To install different versions of Python on Arch Linux without affecting the system's built-in Python, it is recommended to use the following methods:

1. Using `pyenv`#

pyenv is a popular tool that allows you to easily install and manage multiple versions of Python without interfering with the system's default Python version.

It's similar to a virtual machine; you can install different operating systems. If you want to use Windows 7, you create a virtual machine and install Windows 7. If you want to use Windows 10, you create a virtual machine and install Windows 10.

Here, pyenv is intended to switch the system's Python version to whichever Python version you want to install directly, without needing root permissions to install various versions of Python.

Installing `pyenv`#

Install dependencies: pyenv requires some dependencies needed to compile Python.

sudo pacman -S base-devel libffi openssl zlib bzip2 readline sqlite gdbm db gamma libpcap xz tk

Install pyenv: Use pacman to install pyenv.
```
sudo pacman -S pyenv
```
Configure environment variables: Add the pyenv initialization script to your shell configuration file (e.g., ~/.bashrc or ~/.zshrc).

If any of the four commands in this step report an error after execution, you can try using other pyenv commands. If other commands work, you can ignore this and use it normally.
```
echo 'export PATH="$HOME/.pyenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init --path)"' >> ~/.bashrc
echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bashrc
source ~/.bashrc
```

Using `pyenv` to Install Python#

Install a specific version of Python:
```
pyenv install 3.8.10
```
Set the global Python version:
```
pyenv global 3.8.10
```
View installed Python versions:
```
pyenv versions
```
View available Python versions:

You can use the pyenv install --list command to see all available Python versions for installation.
```
pyenv install --list
```
Temporarily switch Python versions

Use the pyenv shell command to temporarily set the Python version for the current terminal session. This version is only effective in the current terminal session and will be lost when the terminal is closed.
```
pyenv shell 3.8.10
```