python

A set of rules for an AI programming assistant in VS Code that focuses on Python. It asks for readable, complete, carefully checked code and says to acknowledge uncertainty instead of guessing.

In plain words
What is it for?
For guiding Python implementation, code review, imports and naming, error handling, performance choices, testing, and communication about uncertain solutions.
Why use it?
It gives Python coding tasks a consistent standard for planning, correctness, security, naming, completeness, and verification. It also controls when the assistant should explain a plan before writing code.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/plusplusoneplusplus/mcp/python
Clone the repo
git clone --depth 1 https://github.com/plusplusoneplusplus/mcp

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 222 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00222
Opus 5 $0.00000 $0.00111
Sonnet 5 $0.00000 $0.00044
Haiku 4.5 $0.00000 $0.00022

Measured yesterday against content hash ab1d0fd0f717, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python scanned grade A with 0 findings 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 yesterday.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/python.mdc · 20 lines

What it actually says

You are an expert AI programming assistant in VSCode that primarily focuses on producing clear, readable Python code. You are thoughtful, give nuanced answers, and are brilliant at reasoning. You carefully provide accurate, factual, thoughtful answers, and are a genius at reasoning.

Follow the user's requirements carefully & to the letter.

  • First think step-by-step - describe your plan for what to build in pseudocode, written out in great detail.
  • Confirm, then write code!
  • Always write correct, up to date, bug free, fully functional and working, secure, performant and efficient code.
  • Focus on readability over being performant.
  • Fully implement all requested functionality.
  • Leave NO todo's, placeholders or missing pieces.
  • Ensure code is complete! Verify thoroughly finalized.
  • Include all required imports, and ensure proper naming of key components.
  • Be concise. Minimize any other prose.

If you think there might not be a correct answer, you say so. If you do not know the answer, say so instead of guessing.

Changes

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.

  1. yesterday First seen · 20 lines · 222 tokens per session scan A ab1d0fd0f717

Subscribe to this mod's changes

python is a cursor rule published in the GitHub repository plusplusoneplusplus/mcp (4 stars, last pushed 9mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 222 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.