📘 Manual: Managing Python with Update-Alternatives

The update-alternatives tool creates, removes, maintains, and displays information about the symbolic links comprising the Debian alternatives system.
1. Register Python Versions (Setup)

Before you can switch between versions, you must register them as "alternatives" for the python3 command. The number at the end represents the priority (higher numbers have higher priority in "auto" mode).
Bash

# Register Python 3.10 (Standard Ubuntu 22.04)
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.10 1

# Register Python 3.11 (Your manual install)
sudo update-alternatives --install /usr/bin/python3 python3 /usr/local/bin/python3.11 2

2. Switch Active Version (Config)

Use this command to interactively choose which version of Python should be the active default.
Bash

sudo update-alternatives --config python3

Usage:

    A list of registered versions will appear.

    Type the Selection number and press Enter.

    The version marked with an asterisk * is currently active.

3. View Status (Display)

To see all registered paths, their current priority, and which version is currently being used, use the --display flag.
Bash

update-alternatives --display python3

    Tip: This is useful for confirming if a path is correct or if the system is in "auto" vs "manual" mode.

4. Remove a Version (Remove)

If you no longer want a specific version to be an option (or if you made a typo in the path), use the --remove flag.
Bash

# Syntax: sudo update-alternatives --remove <link_group> <path_to_binary>
sudo update-alternatives --remove python3 /usr/local/bin/python3.11

5. Reset All Alternatives (Wipe)

If the symlinks become broken or you wish to start over, you can remove the entire python3 group.
Bash

sudo update-alternatives --remove-all python3

⚠️ Critical Note for Ubuntu Users

Ubuntu's internal tools (like the terminal and the software updater) are dependent on the specific version of Python that shipped with the OS.

    System Default: Python 3.10

    Risk: Leaving Python 3.11 as the "Active" version indefinitely can cause system scripts to crash.

    Best Practice: Use update-alternatives to switch to 3.11 for your installation/task, then switch back to 3.10 immediately afterward.

Would you like me to generate a script that automates this "switch, install, and switch back" process for you?