When it comes to Python, did you ever find a problem installing or changing the Python version? If yes, then we’re the same. I always have a problem when it comes to changing the Python version and my only solution at that time is just uninstalling Python and re-installing the version that I need.

After dealing with that problem for a long time, I finally found the tools to manage the Python version, named Pyenv.

What is Pyenv?

Basically, Pyenv is a tool to simplify installation and version changing in Python. It helps developers quickly install or change the Python version without needing to change the whole system.

In this post, I will show you how to install pyenv and manage the Python version.

Install Pyenv

To start the installation process, it’s a good idea to update the system packages. Open the terminal and write the command below.

apt update -y

After that, let’s install all Pyenv dependencies.

apt install -y make build-essential libssl-dev zlib1g-dev \
> libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev\
> libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python-openssl\
> git

After that, we will install the latest version on Pyenv. So, we will need to clone from the Pyenv repository.

git clone https://github.com/pyenv/pyenv.git ~/.pyenv

For the last step, we must add pyenv to our path so that the pyenv command is recognized globally.

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init --path)"' >> ~/.bashrc

Finally, to start using pyenv, restart the shell by running:

exec "$SHELL"

Install Python

To check whether pyenv is already installed on our machine, we can use this command.

pyenv --version

In mine, the response is pyenv 2.3.6–13-g4c261e6e, if you do not see a result similar to this, then maybe there is an error in your installation.

To see the available Python version, you can use this command.

pyenv install --list

For example, I will install Python 3.9.15. So the command will be like this.

pyenv install 3.9.15

Don’t worry if your terminal doesn’t return anything, the process takes a while. Maybe you can leave it for a while to make coffee or something.

If the installation is already done, you can verify if the Python version is already installed, you can use the:

pyenv versions

And the result will look like this.

* system (set by /home/user/.pyenv/version)
  3.9.15 

The * means that the system is the default Python version. To set Python 3.9.15 as the default Python, use the command:

pyenv global 3.9.15

After that, check the Python version.

python --version  # or python -V

If the Python version is 3.9.15 or whatever Python version you install, then the Python installation is a success. If you want to add another Python version, you can just use pyenv install <version> and if you want to change the Python version, you can just use pyenv global <version>.