Modern Python

An installable agent plugin containing the use-modern-python skill. It helps coding agents detect a project's minimum supported Python version and apply modern language and standard-library features without exceeding that version.

The skill is shared by Claude Code and Codex. Its detector script is bundled with the skill and requires Python 3.8 or newer.

Note

The version-aware guidance in this skill was inspired by JetBrains’ Modern Go guidelines. This skill applies a similar approach to Python.

Install in Claude Code

Add this repository as a marketplace, then install the plugin:

/plugin marketplace add 353solutions/modern-python
/plugin install modern-python@modern-python-guides

Or load the plugin from a local checkout for one session:

claude --plugin-dir ./plugins/modern-python

The skill appears as /modern-python:use-modern-python.

Install in Codex

Add this repository as a plugin marketplace:

codex plugin marketplace add 353solutions/modern-python
codex plugin add modern-python@modern-python-guides

Or open the plugin browser with codex /plugins, select modern-python-guides, and install Modern Python. The use-modern-python skill is bundled in the plugin and is available when the plugin is enabled; invoke it with $use-modern-python.

For repo-scoped use without installing the plugin, copy plugins/modern-python/skills/use-modern-python into the project's .agents/skills/ directory.

Recommended project instruction

To have the agent use the skill whenever it works on Python files, add an instruction to the project's rules file.

For Claude Code, add this to CLAUDE.md:

When working with Python files, always use the `/modern-python:use-modern-python` skill.

For Codex, add the equivalent instruction to AGENTS.md:

When working with Python files, always use the `$use-modern-python` skill.

What it does

The skill checks version declarations such as requires-python, Poetry, setup.cfg, setup.py, and .python-version. It treats the lowest supported version as the compatibility target, then recommends language and standard library features available at that version. It includes a detector script at skills/use-modern-python/scripts/detect_python_version.py.