🐧🐍 Pyenv & Python 3.12 on Ubuntu — Setup Guide
1. Install System Dependencies
sudo apt update
sudo apt install -y make build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm \
libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
2. Install pyenv
curl https://pyenv.run | bash
If you see
WARNING: Can not proceed... Kindly remove the '/home/USER/.pyenv' directory first— pyenv is already installed, skip this step.
3. Add pyenv to Your Shell (bashrc)
echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc
source ~/.bashrc
Verify pyenv is working:
pyenv --version
# pyenv 2.x.x
4. Install Python 3.12
pyenv install 3.12.0
5. Set the Python Version
Globally (system-wide):
pyenv global 3.12.0
Locally (for a specific project/folder):
cd ~/Desktop/NeSy/backend
pyenv local 3.12.0
The local version creates a
.python-versionfile in the folder and is automatically activated whenever you enter that directory.
6. Check Python Versions
Python versions installed on the system:
ls /usr/bin/python*
Python versions installed via pyenv:
pyenv versions
Example output:
system
* 3.12.0
3.11.5
The * indicates the currently active version.
Check which Python version is currently in use:
python --version
which python
Check which version is active inside the venv:
# (while venv is activated)
python --version
which python
Quick Reference
| Action | Command |
|---|---|
| List all pyenv versions | pyenv versions |
| Install a Python version | pyenv install 3.12.0 |
| Set global version | pyenv global 3.12.0 |
| Set local version | pyenv local 3.12.0 |
| Check current version | python --version |
| Check Python path | which python |
| Create venv | python -m venv .venv |
| Activate venv | source .venv/bin/activate |
| Deactivate venv | deactivate |
| Verify SSL | python -c "import ssl; print(ssl.OPENSSL_VERSION)" |