python-architect

A Python architecture guide covering project structure, package management, formatting, linting, type checking, testing, and automation. Test-driven development means writing tests as part of designing and changing code.

In plain words
What is it for?
Structuring production Python applications, managing environments with uv, checking code with Ruff and mypy, writing pytest tests, and automating checks with Git hooks and GitHub Actions.
Why use it?
It gives one consistent approach to organizing Python projects and catching errors before release.

Skill for Claude CodeCodex

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 skills/niuverse/skills/python-architect
Any agent
npx skills add niuverse/skills --skill python-architect
Clone the repo
git clone --depth 1 https://github.com/niuverse/skills

Made for: Claude Code, Codex.

Per session 143 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,101 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 $0.00143 $0.02101
Opus 5 $0.00072 $0.01051
Sonnet 5 $0.00029 $0.00420
Haiku 4.5 $0.00014 $0.00210

Measured yesterday against content hash b316bc1d56f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-architect 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.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/init_python_project.py, scripts/setup_modern_python.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/python-architect/SKILL.md · 318 lines

How it starts

The opening of the file, as written. The whole thing — 318 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Architect

Expert-level Python software architecture with modern tooling and best practices.

🎯 Philosophy

  • Simplicity over complexity: Simple solutions are easier to maintain
  • Tests as documentation: Well-written tests explain intent
  • Type safety: Use type hints to catch bugs early
  • Automation: Automate checks, formatting, and releases

🛠️ Tech Stack

Tool Purpose Replacement For
uv Package management & virtual envs pip, poetry, pipenv
ruff Linting & formatting flake8, black, isort, pydocstyle
pytest Testing unittest
mypy Type checking -
pre-commit Git hooks -
GitHub Actions CI/CD -

📁 Project Structure

my-project/
├── src/
│   └── my_project/           # Source code
│       ├── __init__.py
│       ├── core/             # Domain logic
│       ├── services/         # Business logic
│       ├── repositories/     # Data access
│       └── api/              # Web interface
├── tests/
│   ├── unit/                 # Unit tests
│   ├── integration/          # Integration tests
│   └── conftest.py          # pytest fixtures
├── docs/                     # Documentation
├── scripts/                  # Utility scripts
├── .github/
│   └── workflows/           # CI/CD
├── pyproject.toml           # Project config (uv, ruff, pytest, mypy)
├── README.md
├── LICENSE
└── .pre-commit-config.yaml

🚀 Quick Start

# Create new project
python scripts/init_python_project.py my-project

# Setup existing project
python scripts/setup_modern_python.py

# Run all checks
python scripts/check_project.py

📋 Best Practices

1. Project Initialization with uv

# Create project
uv init my-project
cd my-project

# Add dependencies
uv add requests pydantic
uv add --dev pytest ruff mypy

# Sync environment
uv sync

2. pyproject.toml Configuration

[project]
name = "my-project"
version = "0.1.0"
description = "A modern Python project"
requires-python = ">=3.11"
dependencies = [
    "pydantic>=2.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=7.0",
    "pytest-cov",
    "ruff>=0.1.0",
    "mypy>=1.0",
    "pre-commit",
]

[tool.ruff]
target-version = "py311"
line-length = 88
select = [
    "E",   # pycodestyle errors
    "F",   # Pyflakes
    "I",   # isort
    "N",   # pep8-naming
    "W",   # pycodestyle warnings
    "UP",  # pyupgrade
    "B",   # flake8-bugbear
    "C4",  # flake8-comprehensions
    "SIM", # flake8-simplify
]
ignore = ["E501"]  # Line too long (handled by formatter)

[tool.ruff.format]
quote-style = "double"
indent-style = "space"

[tool.pytest.ini_options]
testpaths = ["tests"]
python_files = ["test_*.py"]
python_classes = ["Test*"]
python_functions = ["test_*"]
addopts = "-v --tb=short --strict-markers"
markers = [
    "unit: Unit tests",
    "integration: Integration tests",
    "slow: Slow tests",
]

[tool.mypy]
python_version = "3.11"
warn_return_any = true
warn_unused_configs = true
disallow_untyped_defs = true
strict = true

Read the full file on GitHub · 318 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 318 lines · 143 tokens per session scan A b316bc1d56f4

Subscribe to this mod's changes

python-architect is a skill published in the GitHub repository niuverse/skills (2 stars, last pushed 2d ago), licensed MIT. It adds 143 tokens to every session and 2,101 once invoked, about $0.0007 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.

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