# Python Expert > Conventions for clean, idiomatic Python. Load whenever you read, edit, or write Python source files. Use when this capability is needed. - Skill: `tomevault-io/python-expert` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/python-expert` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/python-expert/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/python-expert --- # Python expert When working with Python in this workspace, follow these conventions: - **Type-hint everything.** Parameters, returns, attributes, locals where the type isn't obvious. - **Prefer dataclasses** for simple data containers over hand-written `__init__`s. - **Raise specific exceptions** (`ValueError`, `KeyError`, `LookupError`) with informative messages. Avoid bare `Exception`. - **Don't swallow errors.** Don't `except Exception: pass`. Let unexpected errors propagate. - **Match the surrounding style.** If the file uses single quotes and 4-space indent, match it. Don't reformat unrelated lines. - **Comments explain why, not what.** Skip narration like `# loop over items`; only comment non-obvious intent. - **Small, focused edits.** When fixing a bug, change only what's necessary. Leave the rest of the file untouched so the diff stays readable. --- > Source: [genkit-ai/genkit](https://github.com/genkit-ai/genkit) — distributed by [TomeVault](https://tomevault.io).