Setting Python Version in Ubuntu: Pointing to an Older Version (3.6)

In the world of Linux distributions, Ubuntu plays a significant role in powering many developers' workstations. One common challenge faced by developers switching between different Python versions is pointing their systems to a specific version, such as Python 3.6. This guide will walk you through the process of setting up and using an older version of Python on Ubuntu, particularly version 3.6, a popular choice for many legacy projects and specific applications.

Understanding Pointing to a Python Version

When we say pointing to a Python version, it simply means specifying which version of Python should be used by default in your terminal. This is especially useful when you have multiple Python versions installed and you want to ensure your scripts or applications use a specific one.

The Importance of Python Version Management in Ubuntu

Ubuntu, like most Linux distributions, often comes with Python 2.7 pre-installed and carries the latest version of Python as its default. This can lead to compatibility issues when working with projects that specifically require an older version of Python, such as Python 3.6. The ability to manage Python versions ensures that you can work seamlessly across different projects without conflicts.

Installing Python 3.6 in Ubuntu

As of my last update, Ubuntu officially does not come with Python 3.6 pre-installed. However, this doesn't mean you can't run it. Here's how to install Python 3.6 on your Ubuntu system:

Step 1: Update the Package List

Before installing any new software, it's always a good idea to update the package lists so you have the latest information on what is available:

sudo apt update

Step 2: Download and Install Python 3.6

Since Ubuntu does not provide Python 3.6 by default, you'll need to download it and install it manually. Here are the steps to do this:

Step 2.1: Visit the Python Website

Go to the official Python website () and find the appropriate Python 3.6 package for your operating system.

Once you have the package, proceed to download it.

Step 2.2: Extract the Package

Once the download is complete, extract the package:

tar -xvzf Python-3.6.X.xx.tar.gz

Step 2.3: Install Python 3.6

Now, navigate to the directory where you extracted the files:

cd Python-3.6.X/

In this directory, run the installation script:

sudo ./configure sudo make sudo make install

Step 3: Verify the Installation

After installation, you can verify that Python 3.6 is correctly installed on your system:

python3.6 --version

Pointing to Python 3.6 in Ubuntu

The default Python 3 version on Ubuntu is usually 3.8 or higher. However, you can point your shell to Python 3.6 by using the alias command or by setting an environment variable. Here are two methods:

Method 1: Using an Alias Command

Edit your shell configuration file (usually .bashrc for Bash) and add the following line:

alias pythonpython3.6

Then, reload the configuration file:

source ~

Method 2: Setting an Environment Variable

Alternatively, you can set the PYTHONPATH environment variable to point to Python 3.6:

export PYTHONPATH/usr/local/bin/python3.6

Again, reload your shell configuration to apply the change.

Conclusion

Pointing Python to an older version, such as Python 3.6, on an Ubuntu system gives developers the flexibility to maintain compatibility with specific applications or projects. By following the steps outlined in this guide, you can successfully install and use Python 3.6 on your Ubuntu system, ensuring a smooth development experience.

Additional Resources

For further reading and troubleshooting, consider the following resources:

Python 3 Documentation: Installing Python TechAdmin: How to Install Python 3.6 on Ubuntu Bob Smashes: How to Install Python 3.6 on Ubuntu 18.04