How to Install Python 3.9 on AlmaLinux

Python is one of the most popular programming languages in the world, valued for its simplicity, versatility, and extensive library support. Whether you’re a developer working on web applications, data analysis, or automation, Python 3.9 offers several new features and optimizations to enhance your productivity. This guide will walk you through the process of installing Python 3.9 on AlmaLinux, a community-driven enterprise operating system derived from RHEL.

Why Python 3.9?

Python 3.9 introduces several enhancements, including:

• New Syntax Features:
  • Dictionary merge and update operators (| and |=).
  • New string methods like str.removeprefix() and str.removesuffix().
• Performance Improvements: Faster execution for some operations.
• Improved Typing: Type hints are more powerful and versatile.
• Module Enhancements: Updates to modules like zoneinfo for timezone handling.

Using Python 3.9 ensures compatibility with the latest libraries and frameworks while enabling you to take advantage of its new features.

Prerequisites

Before proceeding, ensure the following:

1. AlmaLinux system: A fresh installation of AlmaLinux with root or sudo privileges.
2. Terminal access: Familiarity with Linux command-line tools.
3. Basic knowledge of Python: Understanding of Python basics will help in testing the installation.

Step 1: Update Your System

Begin by updating your AlmaLinux system to ensure all packages are up-to-date:

sudo dnf update -y

This ensures that you have the latest security patches and package versions.

Step 2: Check the Default Python Version

AlmaLinux comes with a default version of Python, which is used for system utilities. Check the currently installed version:

python3 --version

The default version might not be Python 3.9. To avoid interfering with system utilities, we’ll install Python 3.9 separately.

Step 3: Enable the Required Repositories

To install Python 3.9 on AlmaLinux, you need to enable the EPEL (Extra Packages for Enterprise Linux) and PowerTools repositories.

Enable EPEL Repository

Install the EPEL repository by running:

sudo dnf install -y epel-release

Enable PowerTools Repository

Enable the PowerTools repository (renamed to crb in AlmaLinux 9):

sudo dnf config-manager --set-enabled crb

These repositories provide additional packages and dependencies required for Python 3.9.

Step 4: Install Python 3.9

With the repositories enabled, install Python 3.9:

sudo dnf install -y python39

Verify the Installation

Once the installation is complete, check the Python version:

python3.9 --version

You should see an output like:

Python 3.9.x

Step 5: Set Python 3.9 as Default (Optional)

If you want to use Python 3.9 as the default version of Python 3, you can update the alternatives system. This is optional but helpful if you plan to primarily use Python 3.9.

Configure Alternatives

Run the following commands to configure alternatives for Python:

sudo alternatives --install /usr/bin/python3 python3 /usr/bin/python3.9 1
sudo alternatives --config python3

You’ll be prompted to select the version of Python you want to use as the default. Choose the option corresponding to Python 3.9.

Verify the Default Version

Check the default version of Python 3:

python3 --version

Step 6: Install pip for Python 3.9

pip is the package manager for Python and is essential for managing libraries and dependencies.

Install pip

Install pip for Python 3.9 with the following command:

sudo dnf install -y python39-pip

Verify pip Installation

Check the installed version of pip:

pip3.9 --version

Now, you can use pip3.9 to install Python packages.

Step 7: Create a Virtual Environment

To manage dependencies effectively, it’s recommended to use virtual environments. Virtual environments isolate your projects, ensuring they don’t interfere with each other or the system Python installation.

Create a Virtual Environment

Run the following commands to create and activate a virtual environment:

python3.9 -m venv myenv
source myenv/bin/activate

You’ll notice your terminal prompt changes to indicate the virtual environment is active.

Install Packages in the Virtual Environment

While the virtual environment is active, you can use pip to install packages. For example:

pip install numpy

Deactivate the Virtual Environment

When you’re done, deactivate the virtual environment by running:

deactivate

Step 8: Test the Installation

Let’s create a simple Python script to verify that everything is working correctly.

Create a Test Script

Create a new file named test.py:

nano test.py

Add the following code:

print("Hello, Python 3.9 on AlmaLinux!")

Save the file and exit the editor.

Run the Script

Execute the script using Python 3.9:

python3.9 test.py

You should see the output:

Hello, Python 3.9 on AlmaLinux!

Step 9: Troubleshooting

Here are some common issues you might encounter during installation and their solutions:

1. python3.9: command not found:

   • Ensure Python 3.9 is installed correctly using sudo dnf install python39.
   • Verify the installation path: /usr/bin/python3.9.

2. pip3.9: command not found:

   • Reinstall pip using sudo dnf install python39-pip.

3. Conflicts with Default Python:

   • Avoid replacing the system’s default Python version, as it might break system utilities. Use virtual environments instead.

Step 10: Keeping Python 3.9 Updated

To keep Python 3.9 updated, use dnf to check for updates periodically:

sudo dnf upgrade python39

Alternatively, consider using pyenv for managing multiple Python versions if you frequently work with different versions.

Conclusion

Installing Python 3.9 on AlmaLinux equips you with a powerful tool for developing modern applications. By following this guide, you’ve successfully installed Python 3.9, set up pip, created a virtual environment, and verified the installation. AlmaLinux provides a stable and secure foundation, making it an excellent choice for running Python applications in production.

Whether you’re building web applications, automating tasks, or diving into data science, Python 3.9 offers the features and stability to support your projects. Happy coding!