monty: Skill for Claude Code

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):

mkdir playground

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

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

foo()

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

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