# Python Playground

> Run and test Python code in a dedicated playground directory. Use when you need to execute Python scripts, test code snippets, investigate CPython behavior, or experiment with Python without affecting the main codebase. Use when this capability is needed.

- Skill: `tomevault-io/python-playground` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/python-playground`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/python-playground/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/python-playground

---


# Python Playground

Run Python code in an isolated playground directory for testing and experimentation.

## Instructions

1. First, ensure the playground directory exists. If the `playground` directory doesn't already exist, run `mkdir playground`.
2. Use the Write tool to create the Python file at `playground/test.py`
3. Run with: `uv run playground/test.py` to test cpython behavior or `cargo run -- playground/test.py` to test monty behavior

IMPORTANT: Use separate tool calls for each step - do NOT chain commands with `&&`. This allows the pre-approved commands to work without prompting.

## Example workflow

Step 1 - Create directory if it doesn't already exist (Bash, already allowed):

```bash
mkdir playground
```

Step 2 - Write code (use Write tool, not cat):
Write to `playground/test.py`:

```python
def foo():
    raise ValueError('test')

foo()
```

Step 3 - Run script (Bash, already allowed):

```bash
uv run playground/test.py
```

## Guidelines

- The `playground/` directory is gitignored
- Use a different file name for each test you want to run, give the files recognizable names like `test_value_error.py`
- Use `uv run ...` to run scripts (uses project Python)
- Or, `cargo run -- ...` to run scripts using Monty
- Use Write tool for creating files (avoids permission prompts)
- Run mkdir and uv as separate commands (not chained)
- do NOT delete files from playground after you've finished testing

---
> Source: [pydantic/monty](https://github.com/pydantic/monty) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-06-18 -->