Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/HermeticOrmus/python-conventions-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/hermeticormus/python-conventions-skills/python-conventions)<a href="https://agentmods.dev/rules/hermeticormus/python-conventions-skills/python-conventions"><img src="https://agentmods.dev/badge/rules/hermeticormus/python-conventions-skills/python-conventions/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/rules/hermeticormus/python-conventions-skills/python-conventions"><img src="https://agentmods.dev/badge/rules/hermeticormus/python-conventions-skills/python-conventions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00319 |
| Opus 5.5 | $0.00000 | $0.00128 |
| Sonnet 5.5 | $0.00000 | $0.00064 |
| Haiku 4.5 | $0.00000 | $0.00032 |
Grade A, and why
python-conventions scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
- subprocess.run over os.system (with list args, not shell strings) What it actually says
Python conventions (3.11+)
Type discipline
- Type hints on every function, attribute, return
from __future__ import annotationsat top- Pydantic v2 for I/O models
- TypedDict for internal dict shapes
- Literal for string-literal enums
Stdlib preferences
- pathlib.Path over os.path
- dataclasses over manual init
- subprocess.run over os.system (with list args, not shell strings)
- f-strings except in logging (lazy formatting)
- match statements for tagged-union dispatch
Async
- async def end-to-end (httpx, not requests)
- TaskGroup for structured concurrency (3.11+)
- Never time.sleep in async code
Logging
- structlog or stdlib with structured extras
- No print() in library code
- Lazy formatting:
logger.info("user %s", id)not f-string
Tooling
- ruff (lint + format)
- mypy --strict
- pytest with fixtures
- uv over pip
Banned
- Bare except
- Mutable default arguments
from foo import *- eval/exec on user input
- Stringly-typed return contracts
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 54 lines · 0 tokens per session scan A e0c2e971f71e
python-conventions is a cursor rule published in the GitHub repository HermeticOrmus/python-conventions-skills (2 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 319 tokens. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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