files-edit-tomllisted

Use when creating or editing a TOML file (pyproject.toml, config.toml, a tool's .toml config) - adding or changing a key, bumping a version/value, editing a table or array - instead of hand-editing it or using sed/regex, which corrupt structure or silently drop comments. Covers tomllib (read), tomlkit (round-trip edit that PRESERVES comments and formatting), and rtoml/tomli_w (write).
bitranox/bitranox-skills · ★ 1 · AI & Automation · score 57

Install: claude install-skill bitranox/bitranox-skills

# Edit TOML with a Python library, never by hand ## Overview Round-trip TOML through a Python parser, then re-load to confirm it parses. Editing TOML as raw text (sed/regex/manual) breaks the classic things: a value placed under the wrong table, a broken array, a mangled quote - and worst, it churns or DROPS the comments and formatting that files like `pyproject.toml` rely on. A library write is valid by construction; re-loading verifies it. ## Library - pick by whether comments must survive - **`tomllib`** (stdlib, 3.11+) - **read only**, no writer. `tomllib.load(f)` (binary mode). The default for reading. - **`tomlkit`** - **the right tool for EDITING an existing file** (e.g. `pyproject.toml`): a style- preserving round-trip that keeps comments, key order, and whitespace. Use this whenever the file has comments or hand-formatting you must not lose. - **`rtoml`** - fast read/write; **does NOT preserve comments**. Fine for machine-owned data files. - **`tomli_w`** - minimal writer (`tomli` + `tomli_w`); also **drops comments**. Pre-3.11 read companion is `tomli`. See **bitranox:coding-python-use-modern-libraries** for the wider list. Reach for the structured editors for the other formats too: **bitranox:files-edit-json**, **bitranox:files-edit-yml**, **bitranox:files-edit-xml**. ## Pattern: edit an existing file (preserve comments) with tomlkit ```python import tomlkit from pathlib import Path path = Path("pyproject.toml") doc = tomlkit.parse(path.read_text(en