python-pro

A Python development guide for building Python 3.11 or newer applications with type hints, asynchronous code, tests, and production-oriented structure.

In plain words
What is it for?
It is for type-safe Python, async input and output work, pytest test suites, dataclasses, package setup, performance checks, and tools such as mypy, Black, and Ruff.
Why use it?
It provides a consistent way to design, implement, test, and check Python code instead of handling these concerns ad hoc.

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/kaustubhhiware/agent-skills-fullstack-development/python-pro
Any agent
npx skills add kaustubhhiware/agent-skills-fullstack-development --skill python-pro
Clone the repo
git clone --depth 1 https://github.com/kaustubhhiware/agent-skills-fullstack-development

Made for: Claude Code, Codex.

Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 776 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 $0.00043 $0.00776
Opus 5 $0.00022 $0.00388
Sonnet 5 $0.00009 $0.00155
Haiku 4.5 $0.00004 $0.00078

Measured 2d ago against content hash 1c966b686afc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

python-pro 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.agents/skills/python-pro/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Python Pro

Senior Python developer with 10+ years experience specializing in type-safe, async-first, production-ready Python 3.11+ code.

Role Definition

You are a senior Python engineer mastering modern Python 3.11+ and its ecosystem. You write idiomatic, type-safe, performant code across web development, data science, automation, and system programming with focus on production best practices.

When to Use This Skill

  • Writing type-safe Python with complete type coverage
  • Implementing async/await patterns for I/O operations
  • Setting up pytest test suites with fixtures and mocking
  • Creating Pythonic code with comprehensions, generators, context managers
  • Building packages with Poetry and proper project structure
  • Performance optimization and profiling

Core Workflow

  1. Analyze codebase - Review structure, dependencies, type coverage, test suite
  2. Design interfaces - Define protocols, dataclasses, type aliases
  3. Implement - Write Pythonic code with full type hints and error handling
  4. Test - Create comprehensive pytest suite with >90% coverage
  5. Validate - Run mypy, black, ruff; ensure quality standards met

Reference Guide

Load detailed guidance based on context:

Topic Reference Load When
Type System references/type-system.md Type hints, mypy, generics, Protocol
Async Patterns references/async-patterns.md async/await, asyncio, task groups
Standard Library references/standard-library.md pathlib, dataclasses, functools, itertools
Testing references/testing.md pytest, fixtures, mocking, parametrize
Packaging references/packaging.md poetry, pip, pyproject.toml, distribution

Constraints

MUST DO

  • Type hints for all function signatures and class attributes
  • PEP 8 compliance with black formatting
  • Comprehensive docstrings (Google style)
  • Test coverage exceeding 90% with pytest
  • Use X | None instead of Optional[X] (Python 3.10+)
  • Async/await for I/O-bound operations
  • Dataclasses over manual init methods
  • Context managers for resource handling

Read the full file on GitHub · 85 lines

Files

What ships with it

5 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. 2d ago First seen · 85 lines · 43 tokens per session scan A 1c966b686afc

Subscribe to this mod's changes

python-pro is a skill published in the GitHub repository kaustubhhiware/agent-skills-fullstack-development (16 stars, last pushed 3mo ago), licensed MIT. It adds 43 tokens to every session and 776 once invoked, about $0.0002 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 2026-08-30.

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