Upgrade Python to latest version (3.10) on Ubuntu Linux

Last Updated: 2022-08-11

Linux systems come with Python install by default, but, they are usually not the latest. Python also cannot be updated by a typical apt upgrade command as well.

To check the version of Python installed on your system run

python3 --version

python keyword is used for Python 2.x versions which has been deprecated

In this guide we will

1. Update Python to the latest version
2. Fix pip & other Python related issues
3. While doing the above two, ensure your Ubuntu which is heavily dependent on Python does not break

Updating Python to the latest version

Ubuntu's default repositories do not contain the latest version of Python, but an open source repository named deadsnakes does.

Python3.10 is not officially available on Ubuntu 20.04, ensure you backup your system before upgrading.

Step 1: Check if Python3.10 is available for install

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update

Check if Python 3.10 is available by running

apt list | grep python3.10

This will produce the below result, if you see python3.10 it means you can install it

Step 2: Install Python 3.10

Now you can install Python 3.10 by running

sudo apt install python3.10

Now though Python 3.10 is installed, if you check the version of your python by running python3 --version you will still see an older version. This is because you have two versions of Python installed and you need to choose Python 3.10 as the default.

Step 3: Set Python 3.10 as default

Steps beyond here are tested on Ubuntu 20.04 in VM & WSL2, but are experimental , proceed at your own risk.

Changing the default alternatives for Python will break your Gnome terminal. To avoid this, you need to edit the gnome-terminal configuration file.

Open the terminal and run:

sudo nano /usr/bin/gnome-terminal

In first line, change #!/usr/bin/python3 to #!/usr/bin/python3.8. Press Ctrl +X followed by enter to save and exit.

Then save and close the file.

Next, update the default Python by adding both versions to an alternatives by running the below

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.9 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.10 2

Now run

sudo update-alternatives --config python3

Choose the selection corresponding to Python3.10 (if not selected by default).

Now run python3 --version again and you should see the latest Python as the output.

Fix pip and disutils errors

Installing the new version of Python will break pip as the distutils for Python3.10 is not installed yet.

Fix Python3-apt

Running pip in terminal will not work, as the current pip is not compatible with Python3.10 and python3-apt will be broken, that will generate an error like

Traceback (most recent call last):   
    File "/usr/lib/command-not-found", line 28, in <module>     
        from CommandNotFound import CommandNotFound   
    File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 19, in <module>     
        from CommandNotFound.db.db import SqliteDatabase   
    File "/usr/lib/python3/dist-packages/CommandNotFound/db/db.py", line 5, in <module>     
        import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'

To fix this first remove the current version of python3-apt by running

sudo apt remove --purge python3-apt

Then do some cleanup

sudo apt autoclean

Finally, reinstall python3-apt by running

sudo apt install python3-apt

Install pip & distutils

Running pip will still throw an error pip: command not found. We need to install the latest version of pip compatible with Python 3.10.

Also, if try to manually install the latest version of pip, it will throw an error like

ImportError: cannot import name 'sysconfig' from 'distutils' 
(/usr/lib/python3.10/distutils/__init__.py)

Or you might also see an error stating No module named 'distutils.util'. This is because the distutils module is not installed yet, to install run the below command

sudo apt install python3.10-distutils

Now you can install pip by running

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
sudo python3.10 get-pip.py

If you get an error like bash: curl: command not found then you need to install curl first by running sudo apt install curl

Now you can run pip and you should see the output of pip --version

Fix pip-env errors when using venv

When you try to create a new virtual environment using python -m venv env, you may into the following error.

Error: Command '['/path/to/env/bin/python3', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1

You can fix this by reinstalling venv by running

sudo apt install python3.10-venv

All should be done now. It is complicated, but this is how you update Python to latest version.

Extra

If you have oh-my-zsh installed, you can avoid typing out python3 by running

echo "alias py=/usr/bin/python3" >> ~/.zshrc
echo "alias python=/usr/bin/python3" >> ~/.zshrc

Now you can run your files with py or python.