python-pro

An agent skill by Jeffallan, from Jeffallan/claude-skills. Tags: automation, code-quality, debugging, python, testing.

What it does

Use when building Python 3.11+ applications requiring type safety, async programming, or robust error handling. Generates type-annotated Python code, configures mypy in strict mode, writes pytest test suites with fixtures and mocking, and validates code with black and ruff. Invoke for type hints, async/await patterns, dataclasses, dependency injection, logging configuration, and structured error handling.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add Jeffallan/claude-skills --skill python-pro

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/Jeffallan/claude-skills
cp -r claude-skills/skills/python-pro ~/.claude/skills/python-pro

Safety box score

Grade C, moderate risk: 21 of 100 risk points, rated 2026-10-17. The grade rates what the skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. How the score works.

This is a Python development skill that helps generate type-checked code, tests, and packaging config; it mostly stays inside the project tree but includes standard build/install tooling. The main risks are local code execution during installs/tests and the ability to publish artifacts to external package indexes.

Category levels, from 0 (none) to 3 (high)
Category	Level	Why
Code & shell execution	1 (low)	It explicitly recommends running local tooling such as `pip install -e .`, `pip install -e ".[dev]"`, `pytest`, `mypy --strict`, `black`, and `ruff`, which executes commands in the workspace.
Network access	1 (low)	The references include outbound-service examples and URLs, such as `httpx.AsyncClient().get(url)` and PyPI/TestPyPI endpoints like `https://test.pypi.org/simple/`, so generated code or packaging steps may contact remote hosts.
Filesystem reach	1 (low)	It focuses on normal project files (`pyproject.toml`, `src/`, `tests/`) and editable installs, but does not indicate writes outside the repo or destructive file operations.
Secrets & credentials	0 (none)	There is no instruction to read, request, or expose tokens, passwords, keychains, `.env` files, or browser sessions.
Privilege & persistence	0 (none)	No `sudo`, global service registration, shell startup edits, or OS-level configuration changes are requested.
Instruction hijack surface	0 (none)	I found no text that tells the agent to ignore its rules, skip confirmations, follow fetched instructions, or hide behavior.
Irreversible actions	3 (high)	`references/packaging.md` includes direct publication commands like `poetry publish` and `twine upload dist/*`, which can push artifacts externally with irreversible blast radius.
Transparency	0 (none)	All shipped files are readable Markdown; there are no binaries, generated blobs, or unreviewable installers.

Before installing

Read `references/packaging.md` first, especially `poetry publish` and `twine upload` commands.
Use a fresh virtualenv with no production credentials before trying the install/test commands.
If you plan to use the networking examples, point them at a local mock server first and verify nothing unexpected leaves the machine.

Rated 2026-10-17 by an automated review of 6 files from the skill's repository.

Source

Repository: Jeffallan/claude-skills (all skills from this repository)
Path: skills/python-pro/SKILL.md
Branch: main
Updated: 2026-09-19

mutation-testing — Configures mewt or muton campaigns, analyzes surviving mutants, and investigates bugs exposed by testing gaps.
check-compiler-errors — Run compile and type-check commands and report failures
code-improver — Runs an autonomous review-and-fix improvement loop over any code target — a skill, plugin, module, or directory — using a reviewer the user names.
control-cli — Build or adapt a local harness to drive, inspect, and profile an interactive CLI or TUI without external services.
control-ui — Build or adapt a local browser/CDP harness to drive and inspect a web, IDE, or Electron UI.
modern-python — Configures Python projects with modern tooling (uv, ruff, ty). Use when creating projects, writing standalone scripts, or migrating from pip/Poetry/mypy/black.