A set of modern Python coding rules focused on Flask web applications and SQLite databases. It also describes using uv to manage Python versions, packages, environments, and commands.

Use it when building or reviewing Flask and SQLite applications, managing dependencies with uv, and applying tools such as Black and Ruff.

It gives Python projects consistent choices for setup, dependency management, formatting, linting, and common web-and-database patterns.

python — Cursor rule by mitas

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/mitas/cursor-rules/python

Clone the repo

git clone --depth 1 https://github.com/mitas/cursor-rules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.

When invoked 1,882 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.

Model	Per session	Once invoked
Fable 5	$0.00000	$0.01882
Opus 5	$0.00000	$0.00941
Sonnet 5	$0.00000	$0.00376
Haiku 4.5	$0.00000	$0.00188

Measured yesterday against content hash cf3583b4b2e2, 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 · 248 lines

How it starts

The opening of the file, as written. The whole thing — 248 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Best Practices

Using uv for Python Development

Use uv instead of standard Python commands for improved performance
Run Python scripts with: uv run python script.py instead of python script.py
Create virtual environments with: uv venv instead of python -m venv
Install packages with: uv pip install package instead of pip install package
Manage dependencies with uv instead of poetry or pip-tools:
- uv pip compile pyproject.toml -o requirements.txt to generate requirements
- uv sync to install dependencies from lockfile (preferred method)
- uv pip sync requirements.txt as alternative for requirements.txt files
- uv add package to add a dependency to a project
- uv remove package to remove a dependency from a project
Run tools without installing with: uvx tool-name (e.g., uvx pytest)
Install specific Python versions: uv python install 3.11
Use specific Python version: uv run --python 3.11 script.py
Pin Python version for a project: uv python pin 3.11
For detailed uv tool usage, see UV Tool Usage

Code Formatting and Linting

Format code with Black through uv: uv run black .
Lint and fix code with Ruff: uv run ruff check --fix .

Add pre-commit hooks for Ruff and Black:

- repo: https://github.com/astral-sh/ruff-pre-commit
  rev: v0.3.0
  hooks:
    - id: ruff
      args: [--fix]
    - id: ruff-format

Configure all tools in pyproject.toml:

[tool.black]
line-length = 79
target-version = ["py313"]
include = '\.pyi?$'

[tool.ruff]
target-version = "py313"
line-length = 79

[tool.ruff.lint]
select = ["E", "F", "B", "I"]
ignore = ["E203", "E501"]  # Ignore whitespace before ':' and line length

Run Black and Ruff together: uv run bash -c "ruff check --fix . && black ."

Project Structure

Use src-layout with src/your_package_name/
Place tests in tests/ directory parallel to src/
Keep configuration in config/ or as environment variables
Store requirements in pyproject.toml (preferred with uv)
Place static files in static/ directory
Use templates/ for Jinja2 templates

Read the full file on GitHub · 248 lines

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.

yesterday First seen · 248 lines · 1,882 tokens per session scan A cf3583b4b2e2

Subscribe to this mod's changes

python is a cursor rule published in the GitHub repository mitas/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,882 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.

Databases Languages

python

Getting it into your agent

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Python Best Practices

Using uv for Python Development

Code Formatting and Linting

Project Structure

What this file has done since we first saw it

Other cursor rules, from other repositories

angular-20

dev-standard

typescript

coolify-ai-docs

python_lib

specs