Mastering Python Skill

What it does

When your agent uses it

• Asked to write Python code
• Explain Python concepts
• Set up a Python project
• Configure Poetry

Example prompts

• “write Python code”
• “explain Python concepts”
• “set up a Python project”
• “/mastering-python-skill”

Requirements

• Python 3
• Docker
• Pre-approved tools (allowed-tools): Read, Write, Bash, Edit, Glob, Grep

Workflow steps

4 steps, taken from the step headings in SKILL.md.

1. 1Setup
2. 2Develop
3. 3Validate
4. 4Deploy

What it can do on your machine

Read from SKILL.md and the folder at commit 8339623. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Bash
  • Edit
  • Glob
  • Grep

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • python
  • ruff
  • poetry
  • mypy
  • pytest

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • httpbin.org

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Mastering Python Skill loads about 1.4k tokens when it runs, and up to ~111k if it reads all its reference files. Until then it costs about 146 tokens; SKILL.md has 238 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~146

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~111k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NoteMentions a .env fileSKILL.md:122

  i/config_loader.py) | Pydantic settings, .env files, validation | [pydantic-validation.md](references/web-apis/pydantic-

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Read, Write, Bash, Edit, Glob, Grep

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from SpillwaveSolutions/agent-brain at commit 8339623, republished under its MIT licence (© SpillwaveSolutions). 238 words, ~1,422 tokens.

name

mastering-python-skill

description

Modern Python coaching covering language foundations through advanced production patterns. Use when asked to "write Python code", "explain Python concepts", "set up a Python project", "configure Poetry or PDM", "write pytest tests", "create a FastAPI endpoint", "run uvicorn server", "configure alembic migrations", "set up logging", "process data with pandas", or "debug Python errors". Triggers on "Python best practices", "type hints", "async Python", "packaging", "virtual environments", "Pydantic validation", "dependency injection", "SQLAlchemy models".

allowed-tools

Read, Write, Bash, Edit, Glob, Grep

context

fork

agent

senior-python-engineer

metadata.version

2.2.0

metadata.domains

python, testing, packaging, web-development, async, security

- [ ] All tests pass
- [ ] mypy reports no errors
- [ ] ruff check clean
- [ ] Coverage ≥80%
- [ ] No security warnings in dependencies

# Test examples
python sample-cli/async_fetcher.py https://httpbin.org/get
python sample-cli/config_loader.py --show-env
python sample-cli/db_cli.py init --sample-data && python sample-cli/db_cli.py list
python sample-cli/code_validator.py src/

© SpillwaveSolutions, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 31 other files (references) in .claude/skills/mastering-python-skill of SpillwaveSolutions/agent-brain.

• SKILL.md
• .skilz-manifest.yaml
• TOC.md
• references/foundations/code-quality.md
• references/foundations/project-structure.md
• references/foundations/syntax-essentials.md
• references/foundations/type-systems.md
• references/packaging/docker-deployment.md
• references/packaging/poetry-workflow.md
• references/packaging/pyproject-config.md
• references/patterns/async-programming.md
• references/patterns/context-managers.md
• references/patterns/decorators.md
• references/patterns/error-handling.md
• references/patterns/generators.md
• references/production/ci-cd-pipelines.md
• … and 16 more

Open the folder on GitHubat commit 8339623