# Python > Use when writing or refactoring Python code under strict style constraints that require explicit field access, no reflection-style checks, no implicit defaults, and minimal exception handling. - Skill: `tomevault-io/python-5` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/python-5` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/python-5/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-5 --- # Python (Strict) Use this skill when the user wants strict, explicit Python code with low ambiguity and fail-fast behavior. ## Core Rules - Put all imports at the top of the file. - Never use `getattr` or `hasattr`. - Never use `isinstance` type checks. - Do not introduce implicit defaults for required data paths. - Avoid unnecessary `try/except`; only keep exception handling for a clearly required fallback or boundary. ## Implementation Pattern 1) Validate required keys/attributes explicitly. 2) Use direct indexing/attribute access for required fields. 3) For optional branches, use explicit `if "key" in obj` checks. 4) Prefer fail-fast errors over silent fallback behavior. 5) Keep control flow straightforward; avoid defensive swallowing of errors. ## Review Checklist - Imports are module-level and grouped at file top. - No reflective access helpers (`getattr`, `hasattr`). - No runtime type filtering with `isinstance`. - No hidden default values for required fields. - Exception blocks are minimal and justified. - Errors are explicit and actionable. ## References - `references/patterns.md` for quick before/after rewrite patterns. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/jakkusakura) — claim your Tome and manage your conversions.