emliunix/python-uv

Python uv Script Management

Overview

This skill helps create and run Python scripts with automatic dependency management using uv tool. It provides two approaches: inline dependencies (PEP 723) for new/converted scripts, and uv run --with for running existing scripts without modification.

Quick Decision Guide

When to use each approach:

• Inline Dependencies (PEP 723) → Creating new scripts or converting scripts for distribution
• uv run --with → Running existing third-party scripts or quick one-off execution

Approach 1: Inline Dependencies (Recommended)

When to Use

• Creating new standalone scripts
• Scripts that will be shared or distributed
• Long-term maintainable scripts
• Scripts with known, stable dependencies

Basic Template

#!/usr/bin/env -S uv run --script
# /// script
# dependencies = [
#   "package-name>=version",
# ]
# requires-python = ">=3.11"
# ///

import package_name

# Your code here

Creating New Scripts

Use the template assets based on your use case:

1. CLI tool → assets/template-cli.py - Command-line tools with argument parsing
2. Data processing → assets/template-data.py - Pandas-based data analysis
3. API client → assets/template-api.py - REST API integration with auth

Copy the appropriate template and customize for your needs.

Run with: ./script.py or uv run script.py

Converting Existing Scripts

Use the utility script to add inline dependencies:

scripts/add_inline_dependencies.py <script.py> <dep1> [dep2] ...

Example:

scripts/add_inline_dependencies.py myscript.py "requests>=2.31.0" "pyyaml>=6.0"

This will:

• Add PEP 723 metadata block with dependencies
• Update shebang to #!/usr/bin/env -S uv run --script
• Make the script executable
• Preserve original code

Approach 2: uv run --with for Old-Style Scripts

When to Use

• Running existing scripts without modifying them
• Third-party scripts you can't or don't want to modify
• Quick testing with different dependency versions
• When encountering ModuleNotFoundError for unmaintained scripts

Pattern

When you see import errors:

ModuleNotFoundError: No module named 'yaml'

Solution:

uv run --with pyyaml script.py

Multiple dependencies:

uv run --with pyyaml --with requests --with pandas script.py

Common Import-to-Package Mappings

| Import Statement | Package Name | |-----------------|--------------| | import yaml | pyyaml | | import PIL | pillow | | import bs4 | beautifulsoup4 | | import dotenv | python-dotenv |

For complete mapping table and more details, see references/uvx-guide.md

Example Workflows

Workflow 1: Create New CLI Tool

1. Copy template: cp assets/template-cli.py mytool.py
2. Customize the script for your use case
3. Make executable: chmod +x mytool.py
4. Run: ./mytool.py or uv run mytool.py

Workflow 2: Convert Existing Script

1. Identify missing dependencies from imports
2. Run: scripts/add_inline_dependencies.py oldscript.py "dep1>=1.0" "dep2>=2.0"
3. Test: ./oldscript.py

Workflow 3: Quick Fix for Module Errors

1. Encounter: ModuleNotFoundError: No module named 'requests'
2. Run: uv run --with requests script.py
3. If recurring, consider converting to inline dependencies

Best Practices

1. Always specify version constraints (e.g., "requests>=2.31.0") for reproducibility
2. Pin Python version if using newer language features
3. Use --script flag in shebang to enable inline dependency support
4. Test after conversion to ensure all dependencies are captured
5. Prefer inline dependencies for scripts you maintain or distribute
6. Use uv run --with for quick experiments or external scripts

Resources

scripts/

• add_inline_dependencies.py - Add PEP 723 metadata to existing Python scripts

references/

• uvx-guide.md - Comprehensive guide with examples, troubleshooting, and detailed explanations

assets/

• template-cli.py - CLI tool template with Click
• template-data.py - Data processing template with Pandas
• template-api.py - API client template with Requests

Troubleshooting

Script not found: Install uv with brew install uv or curl -LsSf https://astral.sh/uv/install.sh | sh

Module not found during execution: Use uv run --with package-name script.py for quick fix, or add to inline dependencies for permanent solution

Permission denied: Run chmod +x script.py to make executable

For more detailed troubleshooting, see references/uvx-guide.md.