더 나은 파이썬 개발 환경 구축Building a Better Python Development Environment

The annoying parts of Python development

People who try Python for the first time often say it’s easy! But once you get a fair way into real development, you realize it’s the language that feels easy; setting up the development environment has a lot more pain points than in other languages.

1. Managing Python versions
2. Managing packages with pip
3. Setting up virtual environments

Some packages don’t work on Windows, so please don’t develop in Python on Windows itself. Use WSL instead.

Let’s look at how to build a better Python environment.

The trouble with managing Python versions

If you use Python, you hear “its performance lags behind other languages” a lot. And every time, lines like this reel you in:

Release notes: The new version 3.XX brings a performance boost of X percent…
Me: “OK, upgrading Python right now!”

But when you actually do that…

1. Packages that worked on the previous version stop working.
2. One server runs Python 3.8, another runs 3.12…
3. Even upgrading the Python version that ships with the system doesn’t go smoothly.

> Managing Python versions is tougher than you think.

Python version management: pyenv

Installing and managing multiple Python versions by hand is a real hassle. My recommendation is pyenv. pyenv is a tool for installing and managing multiple versions of Python, and it lets you switch easily between the versions different projects need.

Installing it is simple. Just follow the pyenv GitHub page.

1. Install

You can install it with brew or curl.

$ curl https://pyenv.run | bash

2. Configure the shell

After installing, add the following lines to your shell config file (~/.bashrc, ~/.zshrc, etc.).

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. Verify the installation

Once it’s installed, restart your shell and check that it installed correctly.

$ pyenv --version

4. Install a specific version

Now that it’s installed, check which Python versions are available and install a specific one.

$ pyenv install --list

$ pyenv install 3.8.10

5. Set the version

The global option sets the default version for the whole system. Conversely, local sets the version for a specific directory.

$ pyenv global 3.8.10

$ cd my_project
$ pyenv local 3.7.9

6. List available versions

You can see the list of Python versions currently installed.

$ pyenv versions

The pain of managing packages with pip

pip was first created in 2008. Short for “package installer for Python,” it’s the Python package manager and is included as part of the standard library.

At first, pulling in the packages you need with pip is really convenient. But problems start once the packages those packages depend on get dragged in along with them.

1. Where did this package come from? Can I delete it?
2. Another package uses this one too, but the versions don’t match?
3. Which packages did I actually install?

pip is convenient, but as the number of installed packages grows, you can basically consider them unmanaged. Often you install packages and they never make it into requirements. Many times you don’t even know since when, which package, went missing from where, and how.

Package management: Poetry

There are several ways to solve pip’s package management problems, but of the ones I’ve tried, I recommend Poetry the most.

Poetry is a tool for managing Python packages and projects. It makes dependency management easy and helps you set up project environments more efficiently. Poetry offers a range of features, including installing dependencies, packaging projects, and publishing.

Installing it is simple. Just follow the Poetry installation page.

1. Install pipx

pipx is a tool that lets you install and run Python applications in isolated virtual environments. Install pipx.

$ sudo apt update
$ sudo apt install pipx
$ pipx ensurepath
$ sudo pipx ensurepath --global

2. Install Poetry with pipx

Install Poetry with the command below.

$ pipx install poetry

3. Verify the Poetry installation

Check that Poetry installed correctly.

$ poetry --version

4. Initialize a project with Poetry

Go to the project folder where you want to use Poetry and set it up. The init command creates the pyproject.toml file that Poetry uses. Anyone with Poetry installed can use that file to easily reproduce the same environment.

• -n: skip the interactive prompts
• --python: specify the Python version, following the SemVer (Semantic Versioning) rules.

$ poetry init -n --python=^3.12

5. Add and remove packages

The add command adds a package. Added packages are recorded in the pyproject.toml file. The remove command removes a package.

You can assign a group when installing a package. This is handy for things like installing only certain groups, or installing everything except certain groups.

$ poetry add fastapi

$ poetry remove fastapi

$ poetry add mypy -G dev

6. Install Poetry packages

The install command installs every package recorded in the pyproject.toml file, regardless of group. You can also install only specific groups, or exclude some.

$ poetry install

$ poetry install --with dev

$ poetry install --without test,docs

7. Where the virtual environment (.venv) is created

With the default settings, installing packages creates each virtual environment (.venv) in a default folder managed by Poetry.

You can also have the virtual environment created inside the project. The option below makes the virtual environment (.venv) get created inside the project where the pyproject.toml file lives.

$ poetry config virtualenvs.in-project true

Wrapping up

With Python, you often need to use different versions for different projects. In that case, pyenv makes it easy to manage multiple Python versions.

Package management with pip gets harder as a project grows, so use Poetry to manage packages clearly and set up virtual environments with ease.

That’s how to build a better Python development environment! There are plenty of other management tools suited to different situations, so find the way of setting up a Python development environment that works for you. 😊