python-stack

A set of conventions for building Python projects, covering Python versions, dependency management, code style, type hints, documentation, testing, and asynchronous code.

In plain words
What is it for?
Use it when starting or configuring a Python project, adding packages, setting up linting and testing, choosing project structure, or reviewing Python practices.
Why use it?
It removes repeated decisions about which tools and project practices to use. Following the same setup makes Python projects easier to run, review, test, and maintain.

Command for Gemini CLI

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 commands/mfmezger/ai_agent_dotfiles/python-stack
Clone the repo
git clone --depth 1 https://github.com/mfmezger/ai_agent_dotfiles

Made for: Gemini CLI.

Per session 124 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,655 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 $0.00124 $0.01655
Opus 5 $0.00062 $0.00827
Sonnet 5 $0.00025 $0.00331
Haiku 4.5 $0.00012 $0.00166

Measured 2d ago against content hash 04c79fa104cb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-stack 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 2d 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.

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.

gemini/.gemini/commands/python-stack.md · 192 lines

How it starts

The opening of the file, as written. The whole thing — 192 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Engineering Stack

Standard tooling and conventions for Python projects. When making recommendations or scaffolding projects, prefer these tools over alternatives unless the user explicitly requests otherwise.

Python Version

Use Python 3.13 or 3.14. Target the latest stable release for new projects.

Package and Dependency Management

uv is the standard package and dependency manager. It replaces pip, Poetry, and Conda.

  • Use uv init to scaffold new projects
  • Use uv add <package> to add dependencies (not pip install)
  • Use uv sync to install from lockfile
  • Use uv run to execute scripts/commands in the project environment
  • Use uvx to run CLI tools without installing them (e.g., uvx ruff check, uvx ty)
  • pyproject.toml is the single source of truth for project metadata and dependencies

Coding Standards

MUST DO

  • Type hints for all function signatures and class attributes
  • Use X | None instead of Optional[X] (Python 3.10+)
  • PEP 8 compliance (enforced via ruff)
  • Comprehensive docstrings in Google style for public APIs
  • Test coverage exceeding 90% with pytest
  • Async/await for I/O-bound operations
  • Dataclasses over manual __init__ methods (or Pydantic models when validation is needed)
  • Context managers for resource handling

MUST NOT DO

  • Skip type annotations on public APIs
  • Use mutable default arguments
  • Mix sync and async code improperly
  • Ignore ty errors in strict mode
  • Use bare except: clauses
  • Hardcode secrets or configuration (use pydantic-settings)
  • Use deprecated stdlib modules (use pathlib not os.path)

Code Quality

File Paths — pathlib

Always use pathlib.Path for file and directory operations. Do not use os.path or string manipulation for paths.

Console Output — Rich

Use Rich for terminal output, including formatted text, tables, and progress bars. Use rich.progress as the default for progress indicators.

Logging — Loguru

Use Loguru for application logging. Prefer structured, contextual logs over ad hoc print() debugging.

Read the full file on GitHub · 192 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.

  1. 2d ago First seen · 192 lines · 0 tokens per session scan A 04c79fa104cb

Subscribe to this mod's changes

python-stack is a command published in the GitHub repository mfmezger/ai_agent_dotfiles (5 stars, last pushed 1mo ago), licensed MIT. It adds 124 tokens to every session and 1,655 once invoked, about $0.0006 per session on Opus 5. 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.