Pyenv, Pipenv

python

Pyenv

Allows to have multiple python versions.

Managing Multiple Python Versions on Arch Linux

To manage multiple Python versions on Arch Linux, we recommend using pyenv. This tool allows you to easily install and switch between different Python versions.

Setting Up pyenv on Arch Linux with zsh

  1. Install pyenv and dependencies:

sudo pacman -S --needed base-devel openssl zlib xz

curl https://pyenv.run | bash
  1. Configure pyenv for zsh:

Add the following lines to your ~/.zshrc file:


export PATH="$HOME/.pyenv/bin:$PATH"

eval "$(pyenv init --path)"

eval "$(pyenv init -)"

eval "$(pyenv virtualenv-init -)"
  1. Apply the changes by restarting your shell or sourcing the configuration:

source ~/.zshrc
  1. Install the desired Python versions:

pyenv install 3.10.12

pyenv install 3.11.4
  1. Set a global Python version (optional):

pyenv global 3.10.12
  1. Set a Python version for a specific project:

cd your_project_directory

pyenv local 3.11.4
  1. Verify the current Python version:

python --version

By using pyenv, you can manage multiple Python versions seamlessly on your Arch Linux system without impacting your global Python environment.

Pipenv

Introduction to Pipenv

Pipenv is a tool that aims to bring the best of all packaging worlds (bundling, dependency management, and virtual environments) to the Python world. It automatically creates and manages a virtual environment for your projects, as well as adds/removes packages from your Pipfile as you install/uninstall packages. It also generates the Pipfile.lock, which is used to produce deterministic builds.

Why Use Pipenv?

  1. Simplified Dependency Management: Pipenv replaces the combination of requirements.txt and virtualenv with a single tool that handles both package dependencies and virtual environments.

  2. Environment Consistency: The Pipfile.lock ensures that all installations are reproducible, locking the exact versions of dependencies.

  3. Security: Pipenv checks for known security vulnerabilities in your dependencies.

  4. User-Friendly: Pipenv provides a simple command-line interface that is easier to use than managing virtual environments and dependencies manually.

Installing Pipenv

Since you installed Pipenv using pacman -S python-pipenv, it means you are on an Arch-based Linux distribution. If others need to install it, they can do so using the following:


pacman -S python-pipenv

Alternatively, Pipenv can be installed via pip:


pip install pipenv

Using Pipenv

Here is a step-by-step guide on how to use Pipenv for your Python projects.

1. Creating a New Project

Navigate to your project directory:


mkdir myproject

cd myproject

Create a new virtual environment and Pipfile:


pipenv install

2. Installing Packages

To install a package and add it to your Pipfile, use:


pipenv install <package_name>

For example, to install requests:


pipenv install requests

To install a development-only package:


pipenv install --dev <package_name>

For example, to install flake8 for development:


pipenv install --dev flake8

3. Uninstalling Packages

To uninstall a package and remove it from your Pipfile:


pipenv uninstall <package_name>

4. Activating the Virtual Environment

To activate the virtual environment, use:


pipenv shell

To exit the virtual environment, simply type exit.

5. Running Commands in the Virtual Environment

You can run commands in the virtual environment without activating it:


pipenv run <command>

For example, to run a Python script:


pipenv run python myscript.py

6. Locking Dependencies

To generate a Pipfile.lock:


pipenv lock

This file will lock the exact versions of your dependencies, ensuring consistent environments across different machines.

7. Checking for Security Vulnerabilities

Pipenv can check for known security vulnerabilities in your dependencies:


pipenv check

8. Listing Installed Packages

To list installed packages:


pipenv graph

This will display a dependency graph of installed packages.

Example Workflow

Here’s an example workflow for setting up a new project:

  1. Set up a new project:

mkdir myproject

cd myproject

pipenv install
  1. Install dependencies:

pipenv install requests

pipenv install --dev flake8
  1. Activate the virtual environment:

pipenv shell
  1. Run your Python script:

python myscript.py
  1. Exit the virtual environment:

exit
  1. Generate a Pipfile.lock:

pipenv lock
  1. Check for vulnerabilities:

pipenv check