Install Python Using Pyenv

Pyenv lets you easily switch between multiple versions of Python. It is simple, unobtrusive, and follows the UNIX tradition of single-purpose tools that do one thing well.

At a high level, pyenv intercepts Python commands using shim executables injected into your PATH, determines which Python version has been specified by your application, and passes your commands along to the correct Python installation.

For more information, visit the pyenv GitHub repository.

Pyenv and Python3 Installation Script

• Connect to your Ultra service via SSH.
• Once connected, execute the following command:

bash <(wget -qO- https://scripts.ultra.cc/util-v2/LanguageInstaller/Python-Installer/main.sh)

• Select the Python version to install by typing 1, 2, 3, 4 or 5 and then press ENTER.
• Wait while the script download and install the necessary files.
• To load Python with pyenv in your shell, execute the following command:

source ~/.profile

Check which Python binary you are currently using by executing which python.

• The below output is what you should see.

ultradocs@pollux:~$ which python
/home/ultradocs/.pyenv/shims/python

Pyenv Usage Guide

In this section, you will learn some basic usage of pyenv. If you are looking for pip usage instructions, see this guide.

List Installed Python Versions

• Execute the following command:

pyenv versions

• Assuming that you used the script to install python 3.9, the output will look like this:

ultradocs@pollux:~$ pyenv versions
  system
* 3.9.13 (set by /home/ultradocs/.pyenv/version)
ultradocs@pollux:~$

• The * beside 3.9.13 means that pyenv has set it as the global python version.

Install other Python versions using Pyenv

• Execute the following command:

pyenv install --list | grep -E " 3.[8-9].*| 3.10.*"

• It will list all versions of python from version 3.8 to version 3.10 available for install via pyenv.
• Example output:

ultradocs@pollux:~$ pyenv install --list | grep -E " 3.[8-9].*| 3.10.*"
  3.8.0
  3.8-dev
  3.8.1
  3.8.2
  3.8.3
  3.8.4
  3.8.5
  3.8.6
  3.8.7
  3.8.8
  3.8.9
  3.8.10
  3.8.11
  3.8.12
  3.8.13
  3.9.0
  3.9-dev
  3.9.1
  3.9.2
  3.9.4
  3.9.5
  3.9.6
  3.9.7
  3.9.8
  3.9.9
  3.9.10
  3.9.11
  3.9.12
  3.9.13
  3.10.0
  3.10-dev
  3.10.1
  3.10.2
  3.10.3
  3.10.4
ultradocs@pollux:~$

• You can install any one of them easily with the following command:

pyenv install -v <version number>

For example:
pyenv install -v 3.10.4

• Since I have also installed python 3.10.4, my pyenv versions output looks like this:

ultradocs@pollux:~$ pyenv install -v 3.10.4
ultradocs@pollux:~$ pyenv versions
  system
  3.10.4
* 3.9.13 (set by /home/ultradocs/.pyenv/version)

• Notice that pyenv is still using 3.9.13 as the global python version.
• This can be changed with the following command:

pyenv global <version>

For example:
pyenv global 3.10.4

• Now pyenv will set python 3.10.4 as the global version.
• Example output:

ultradocs@pollux:~$ pyenv global 3.10.4
ultradocs@pollux:~$ pyenv versions
  system
* 3.10.4 (set by /home/ultradocs/.pyenv/version)
  3.9.13
ultradocs@pollux:~$ python -V
Python 3.10.4

Uninstall a Python version using Pyenv

• Again, list your installed python versions and uninstall using the command given below:

ultradocs@pollux:~$ pyenv versions
  system
* 3.10.4 (set by /home/ultradocs/.pyenv/version)
  3.9.13
ultradocs@pollux:~$ pyenv uninstall 3.9.13
pyenv: remove /home/ultradocs/.pyenv/versions/3.9.13? [y|N] y
pyenv: 3.9.13 uninstalled

• We basically upgraded to python 3.10.4 and removed python 3.9.13.

Uninstall Pyenv and the Python version(s) installed by it

• Execute the following command:

bash <(wget -qO- https://scripts.ultra.cc/util-v2/LanguageInstaller/Python-Installer/main.sh)

Manual Uninstallation

• Execute the following command:

rm -rf ~/.pyenv

• Open ~/.profile for editing with the following SSH command:

nano ~/.profile

• Remove the following lines from it:
• export PYENV_ROOT="$HOME/.pyenv"
• export PATH="$PYENV_ROOT/bin:$PATH"
• eval "$(pyenv init --path)"
• Use the key combination Ctrl + O and press Enter to save the changes.
• Then, use the key combination Ctrl + X to exit the nano text editor.
• Load your new ~/.profile with the following SSH command:

source ~/.profile

If you require further assistance, you can open a support ticket here!

Feedback and suggestions regarding this article are welcome on our Discord server

• Install Python Using Pyenv
• Pyenv and Python3 Installation Script
• Pyenv Usage Guide
• List Installed Python Versions
• Install other Python versions using Pyenv
• Uninstall a Python version using Pyenv
• Uninstall Pyenv and the Python version(s) installed by it
• Manual Uninstallation