Building CLI Tools with Python

import click

@click.command()
@click.option('--name', default='World', help='Name to greet')
@click.option('--count', default=1, help='Number of times to greet')
def hello(name, count):
    """Simple program that greets NAME for a total of COUNT times."""
    for _ in range(count):
        click.echo(f'Hello, {name}!')

if __name__ == '__main__':
    hello()

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

@cli.command()
@click.argument('file', type=click.Path(exists=True))
def process(file):
    """Process a file."""
    click.echo(f'Processing {file}...')

@cli.command()
@click.argument('name')
def delete(name):
    """Delete a resource."""
    if click.confirm(f'Do you want to delete {name}?'):
        click.echo(f'Deleted {name}')

if __name__ == '__main__':
    cli()

# Short and long options
@click.option('--name', '-n', help='Your name')

# Multiple values
@click.option('--files', multiple=True, help='Files to process')

# Choice
@click.option('--format', type=click.Choice(['json', 'yaml', 'csv']))

# Boolean flags
@click.option('--verbose/--quiet', default=False)

# Required option
@click.option('--config', required=True, type=click.Path())

import argparse

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('integers', metavar='N', type=int, nargs='+',
                    help='an integer for the accumulator')
parser.add_argument('--sum', dest='accumulate', action='store_const',
                    const=sum, default=max,
                    help='sum the integers (default: find the max)')
parser.add_argument('--verbose', action='store_true',
                    help='increase output verbosity')

args = parser.parse_args()
print(args.accumulate(args.integers))

parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers(help='available commands')

# Add command
add_parser = subparsers.add_parser('add', help='Add numbers')
add_parser.add_argument('x', type=int, help='First number')
add_parser.add_argument('y', type=int, help='Second number')

# Subtract command
sub_parser = subparsers.add_parser('sub', help='Subtract numbers')

from rich.console import Console
from rich.progress import track
from rich.table import Table

console = Console()

# Styled output
console.print("[bold red]Warning![/bold red] Something went wrong")
console.print("[green]Success![/green] Operation complete")

# Tables
table = Table(title="Star Wars Movies")
table.add_column("Episode", style="cyan")
table.add_column("Title", style="magenta")
table.add_column("Year", justify="right")

table.add_row("IV", "A New Hope", "1977")
table.add_row("V", "The Empire Strikes Back", "1980")

console.print(table)

# Progress bars
for i in track(range(10), description="Processing..."):
    # Do work
    pass

# Using Click
name = click.prompt('Enter your name', default='Anonymous')
password = click.prompt('Password', hide_input=True)

# Using Rich
from rich.prompt import Prompt, Confirm, Password

name = Prompt.ask("Your name?", default="World")
if Confirm.ask("Continue?"):
    pass

import getpass

password = getpass.getpass()

import yaml

def load_config(config_file):
    with open(config_file, 'r') as f:
        return yaml.safe_load(f)

import os

api_key = os.environ.get('API_KEY', 'default_key')

# config.py
import configparser

config = configparser.ConfigParser()
config.read('config.ini')

api_key = config['api']['key']

from setuptools import setup, find_packages

setup(
    name='my-cli',
    version='1.0.0',
    packages=find_packages(),
    include_package_data=True,
    install_requires=[
        'click>=8.0',
        'rich>=10.0',
    ],
    entry_points={
        'console_scripts': [
            'mycli=my_cli.cli:cli',
        ],
    },
    python_requires='>=3.8',
)

[build-system]
requires = ["setuptools>=45", "wheel"]
build-backend = "setuptools.build_meta"

[project]
name = "my-cli"
version = "1.0.0"
dependencies = ["click", "rich"]

[project.scripts]
mycli = "my_cli.cli:cli"

import click
from click import ClickException

@click.command()
def risky_command():
    try:
        # Perform operation
        pass
    except ValueError as e:
        raise click.ClickException(f"Invalid value: {e}")
    except Exception as e:
        raise click.ClickException(f"Unexpected error: {e}")

import click

@click.command()
@click.option('--debug', is_flag=True, help='Enable debug mode')
def command(debug):
    if debug:
        # Set debug logging
        pass
    # Run command

from click.testing import CliRunner

def test_hello():
    runner = CliRunner()
    result = runner.invoke(cli, ['--name', 'Test'])
    assert result.exit_code == 0
    assert 'Hello, Test!' in result.output

def test_missing_option():
    runner = CliRunner()
    result = runner.invoke(cli, [])
    assert result.exit_code == 2

import click

@click.command()
def download():
    with click.progressbar(length=100, label='Downloading') as bar:
        for i in range(10):
            # Simulate download
            bar.update(10)

with click_spinner.spinner():
    # Long running operation
    pass