---
tags:
  - python
  - development
  - guide
  - linux
  - pyenv
  - venv
---

# Setting up a Python Development Environment

This guide details the modern, professional way to set up a Python development environment on Linux. We will use `pyenv` to manage different Python versions and `venv` to create isolated project environments. This prevents the classic "dependency hell" where one project's needs conflict with another's.

## 1. Prerequisites

Compiling Python from source requires a standard set of build tools.

*   **Reference:** [[Post-Install-Config|Post-Install Linux Configuration]]
*   **Action:** Ensure `build-essential`, `curl`, and other dependencies for `pyenv` are installed.
    ```bash
    sudo apt install -y build-essential libssl-dev zlib1g-dev libbz2-dev \
    libreadline-dev libsqlite3-dev curl libncursesw5-dev xz-utils \
    tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
    ```

## 2. Install `pyenv` (Python Version Manager)

`pyenv` lets you install and switch between multiple Python versions on the same machine.

1.  **Run the installer:**
    ```bash
    curl https://pyenv.run | bash
    ```
2.  **Add to your shell:** The script will output instructions to add `pyenv` to your `~/.bashrc` file. It will look similar to this:
    ```bash
    echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
    echo 'command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
    echo 'eval "$(pyenv init -)"' >> ~/.bashrc
    ```
3.  **Reload your shell:** Close and reopen your terminal, or run `exec "$SHELL"`.

## 3. Install a Python Version

With `pyenv` ready, you can install any version of Python.

1.  **Install Python:** Let's install the latest stable version (e.g., 3.12.2).
    ```bash
    pyenv install 3.12.2
    ```
2.  **Set the global default:**
    ```bash
    pyenv global 3.12.2
    ```
3.  **Verify:** `python --version` should now show `3.12.2`.

## 4. Create a Virtual Environment (`venv`)

Never install packages globally. Always create an isolated environment for each project.

1.  **Create a project folder:** `mkdir my-python-project && cd my-python-project`
2.  **Create the environment:**
    ```bash
    python -m venv .venv
    ```
    *(This creates a hidden `.venv` folder containing a copy of Python and `pip`).*
3.  **Activate the environment:**
    ```bash
    source .venv/bin/activate
    ```
    *Your terminal prompt will now change to show `(.venv)`.*

## 5. Install Packages with `pip`

Now that you are "inside" the virtual environment, you can safely install packages.

*   **Install a package:** `pip install requests`
*   **Save dependencies:** `pip freeze > requirements.txt`
*   **Install from a list:** `pip install -r requirements.txt`

To leave the environment, simply type `deactivate`.