Click Patterns

Click Framework Patterns

This skill provides comprehensive Click framework patterns, templates, and examples for building production-ready Python CLIs.

Instructions

When Building a Click CLI

1. Read the appropriate template based on complexity:

   • Simple CLI: templates/basic-cli.py
   • Nested commands: templates/nested-commands.py
   • Custom validators: templates/validators.py

2. Generate new Click project:

   bash scripts/generate-click-cli.sh <project-name> <cli-type>
   

   Where cli-type is: basic, nested, or advanced

3. Study complete examples:

   • examples/complete-example.md - Full-featured CLI
   • examples/patterns.md - Common patterns and best practices

4. Validate your Click setup:

   bash scripts/validate-click.sh <cli-file.py>
   

Core Click Patterns

Command Groups:

@click.group()
def cli():
    """Main CLI entry point"""
    pass

@cli.command()
def subcommand():
    """A subcommand"""
    pass

Options and Arguments:

@click.option('--template', '-t', default='basic', help='Template name')
@click.argument('environment')
def deploy(template, environment):
    pass

Nested Groups:

@cli.group()
def config():
    """Configuration management"""
    pass

@config.command()
def get():
    """Get config value"""
    pass

Parameter Validation:

@click.option('--mode', type=click.Choice(['fast', 'safe', 'rollback']))
@click.option('--count', type=click.IntRange(1, 100))
def command(mode, count):
    pass

Available Templates

1. basic-cli.py - Simple single-command CLI
2. nested-commands.py - Command groups and subcommands
3. validators.py - Custom parameter validators
4. advanced-cli.py - Advanced patterns with plugins and chaining

Available Scripts

1. generate-click-cli.sh - Creates Click project structure
2. validate-click.sh - Validates Click CLI implementation
3. setup-click-project.sh - Setup dependencies and environment

Available Examples

1. complete-example.md - Production-ready Click CLI
2. patterns.md - Best practices and common patterns
3. edge-cases.md - Edge cases and solutions

Requirements

• Python 3.8+
• Click 8.0+ (pip install click)
• Rich for colored output (pip install rich)

Best Practices

1. Use command groups for organizing related commands
2. Add help text to all commands and options
3. Validate parameters using Click's built-in validators
4. Use context (@click.pass_context) for sharing state
5. Handle errors gracefully with try-except blocks
6. Add version info with @click.version_option()
7. Use Rich for beautiful colored output

Common Use Cases

• Building CLI tools with multiple commands
• Creating deployment scripts with options
• Implementing configuration management CLIs
• Building database migration tools
• Creating API testing CLIs
• Implementing project scaffolding tools

Purpose: Provide Click framework templates and patterns for Python CLI development Load when: Building Click CLIs, implementing command groups, or validating CLI parameters